Experimental study of nanoparticle-stabilized foam with VTES surface modifier on generation, foamability, stability and oil recovery enhancement

Experimental study of nanoparticle-stabilized foam with VTES surface modifier on generation, foamability, stability and oil recovery enhancement | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Experimental study of nanoparticle-stabilized foam with VTES surface modifier on generation, foamability, stability and oil recovery enhancement Asena Golmoradi, Rohallah Hashemi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6530385/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 10 Oct, 2025 Read the published version in Scientific Reports → Version 1 posted 12 You are reading this latest preprint version Abstract Gas injection in hydrocarbon reservoirs faces challenges, such as low macroscopic sweep efficiency and poor mobility control due to the low density and viscosity of injected gases, leading to gas fingering and gravity segregation. These problems can be resolved by injection of gas as foam to enhance gas mobility as well as sweep efficiency. However, during the foam injection in hydrocarbon reservoirs, foam stability is a crucial factor to enhance the recovery of the process, which could be improved by nanoparticles. Motivated by this interest, the present study aims to generate and stabilize foam with varying nanoparticle concentrations (0.02 to 0.1 wt%) in combination with a 0.236 wt% SDS surfactant, both in the presence and absence of MgCl₂, K₂SO₄, NaCl, and Na₂SO₄ salts. Techniques such as Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), and Dynamic Light Scattering (DLS) confirm successful NP surface modification. The use of vinyltriethoxysilane (VTES) for nanoparticle surface modification increased foam stability. Additionally, micromodel flooding experiments were conducted, and the results were analyzed to assess the transport properties of the fracture-matrix and the oil recovery characteristics of injection materials, including carbon dioxide gas, SDS solutions, and foams stabilized by silica nanoparticles. According to the findings, the surface modification of silica with VTES results in enhancement of foam stability by 30% increase in foam stability experiments. Furthermore, in comparison with pure SDS foam as base case scenario, adding nano-silica and modified nano-silica into solution caused stability enhancement by 22.3% and 61.1%, accordingly. It should be noted that foam stability was negatively affected by an average of 40–50% in presence of smart ions. In addition, micromodel flooding tests confirmed that surfactant foam containing modified nano-silica achieved the highest oil recovery (48.04%) compared to pure surfactant foam with (31.33%) oil recovery. Physical sciences/Engineering/Chemical engineering Physical sciences/Nanoscience and technology foam surfactant nanoparticles foam stability surface modification micromodel Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 1. Introduction Oil extraction from hydrocarbon reservoirs is carried out using primary, secondary, and tertiary recovery techniques, tailored to the specific characteristics of each reservoir. However, primary and secondary methods typically manage to recover approximately 30–50% of the oil in a typical oil reservoir [ 1 – 3 ]. Enhanced oil recovery (EOR) techniques, including chemical and gas injection, microbial extraction, and thermal extraction, modify the physical and chemical properties of brine/surfactant/crude oil systems, such as interfacial tension (IFT), viscosity, and wettability [ 4 – 7 ]. As an EOR techniques, Carbon dioxide injection into hydrocarbon reservoirs has recently become a promising and effective technique due to its non-toxic, non-polar, and non-flammable nature [ 8 , 9 ]. Although CO 2 injection into oil reservoirs is reasonably efficient, there exists still challenges including low sweep efficiency, gravity segregation, and unfavorable mobility of injecting fluid [ 4 , 10 , 11 ]. As a replacement to mitigate the challenges of gas injection, the use of other methods besides CO 2 injection is of crucial importance for sweep efficiency enhancement [ 12 , 13 ]. Foams are considered as a promising method to overcome the disadvantages of CO 2 injection, enhancing the oil recovery, improving the sweep efficiency as well as reducing the viscous fingering of high-permeability zones [ 14 – 16 ]. In addition, to improve the quality of injected foams and maintaining lamella’s stability, surfactants mixtures, which are also known as surface-active agents, are used in enhancing the stability of foam films[ 17 , 18 ]. In practical implementation, previous studies indicated that the injection of surfactant-containing foam into a porous medium under reservoir conditions could negatively affect foam stability and lead to lamella thinning [ 19 , 20 ]. Nanoparticles (NPs) as foam stabilizer with surfactants has garnered the attention of many researchers due to meager absorption into the rock surface, [ 21 , 22 ]. In previous studies, researchers have investigated the effects of surfactants, NPs, modified NPs, polymers, brine, temperature, and pressure on the stability of foams composed of different components [ 23 , 24 ]. Despite the numerous studies in this research area, more studies are still required to fill the quite significant gap between the understanding and application of foam in field operations. Ramsden in 1903 and Pickering in 1907 introduced an innovative method for stabilizing foam emulsions through the use of NPs, which proved to be both cost-effective and efficient in foam generation [ 25 , 26 ]. Considering the low absorption of anionic surfactant molecules and silica NPs on the surfaces of sandstone reservoir rocks, the reason for using silica NPs and anionic surfactants was to achieve good foam stability [ 27 , 28 ]. The effects of aluminum oxide, titanium oxide, copper oxide, and SiO 2 NPs were examined. Among these NPs, SiO 2 can better improve the stability of foams in the presence of carbon dioxide [ 29 ]. As Simjoo et al. found, foams can remain stable in oil-free and oil-containing environments using diverse commercial surfactants, such as Petrostep SB, Dowfax 8390, C12-15 Enordet, and C14-16 α-olefin sulfonate (AOS). These authors produced foams using the mentioned surfactants without pure alkanes. In the absence of oil, Petrostep SB was the most stable surfactant, whereas AOS exhibited the longest foam longevity when oil was present [ 30 ]. Yekeen et al. confirmed that a surfactant in combination with NPs, particularly with nano-SiO 2 , is more effective than Al 2 O 3 in improving foam stability [ 31 ]. In comparison with surfactants, NPs are less likely to adhere to clay minerals and reservoir rocks during migration. Furthermore, by modifying the surface of NPs, the stability and quality of the foam can be improved due to the silanol group on the surface [ 32 ]. Dimethyldichlorosilane (DMDCS) was used for surface modification of silica NPs, and it was found that the hydrophobicity of the modified silica (MS) NPs results in the highest foam stability compared to the unmodified silica [ 33 ]. Monjezi et al. used modified nanoparticle structures 3-aminopropyltriethoxysilane (APTES) and found that surface modification changes the silica surface, making the NPs more oil-wet (gas-wet) in the oil-water (air-water) system [ 34 ]. Lee et al. reported surface modification of calcium carbonate NPs by methyltrimethoxysilane (MTMS). The formation of large and spherical emulsion droplets with high and low concentrations of MTMS was a result of this work. Additionally, most of the CaCO 3 was surrounded by bubbles, which improved the stability of the foam [ 35 ]. A new foam system with a long half-life and a large foam volume was achieved using hydrophobic SiO 2 NPs and sodium dodecyl benzene sulfonate (SDBS) under reservoir conditions. Furthermore, using foam flooding, this system enhanced oil recovery [ 36 ]. The present study investigates the foam generation quality of sodium dodecyl sulfate (SDS) surfactant as a base case scenario. Subsequently, the same procedure will be implemented using silica nano-particle to observe the alteration in foam properties. In addition, the stability of combined SDS surfactant with modified nano-silica using VTES surface modifier were examined since it has not been previously explored in the literatures. Furthermore, the quality of foam was investigated in more severe condition in presence of varying salinities. Finally, a polymethyl-methacrylate (PMMA) micromodel was used to evaluate the recovery enhancement in different gas and foam injection scenarios. 2. Experimental 2. 1. Materials Sodium dodecyl sulfate (SDS) with a purity of ≥ 98.0% and a molecular weight of 288.38 g/mol was used as the foaming agent. Aluminum oxide (Al₂O₃) and silicon dioxide (SiO₂) nanoparticles (NPs) were obtained from US Research Nanomaterials Inc., and their detailed specifications are presented in Table 1 . Triethoxyvinylsilane (VTES), magnesium chloride (MgCl₂), potassium sulfate (K₂SO₄), sodium chloride (NaCl), and sodium sulfate (Na₂SO₄), each with a purity of ≥ 98.0%, were procured from Merck Chemical Company (Darmstadt, Germany). Carbon dioxide gas, used for foam generation, was supplied by Parsan Gas Company (Isfahan, Iran). Crude oil, with a density of 0.89 g/mL and a viscosity of 30.2 cp at 25°C, was obtained from an oil reservoir located in southwestern Iran. All experiments were conducted using deionized water to ensure consistency and minimize impurities. Table 1 Chemical and physical properties of studied NPs Characteristics Nanoparticle form Size (nm) Density [g/cm 3 ] Specific surface area [m 2 g] Silicon dioxide )SiO 2 ( Spherical 20–30 2.4 260 Aluminum oxide (Al 2 O 3 ) Nearly spherical 10–20 3.89 340 2. 2. Methods 2.2.1. Characterization of Silica and Aluminum Oxide Nanoparticles The SiO 2 and Al 2 O 3 NPs were characterized through X-ray diffraction and field-emission scanning electron microscopy (FE-SEM). The diameters of silica and aluminum oxide NPs are approximately in the ranges of 20–30 nm and 50–200 nm, respectively, and the results can be observed in Figs. 1 and 2. It should be noted that some particle sizes were demonstrated in both pictures. It is clear that there exists agglomeration of NPs in the presented images. The XRD analysis of SiO 2 and Al 2 O 3 was demonstrated in Figs. 3 , 4 . As shown, a broad peak at 22° (2-Theta) is characteristic of amorphous silica, indicating the absence of long-range crystalline order. Conversely, the XRD pattern of crystalline Al₂O₃ exhibits distinct peaks, corresponding to specific crystallographic planes. For the alumina nanoparticles (NPs), the pattern clearly displays multiple sharp and intense peaks, confirming the crystalline nature of the Al₂O₃ nanoparticles. The positions of these sharp peaks align with standard reference patterns for γ-Al₂O₃ (gamma phase) [ 37 ]. Notably, the absence of additional peaks suggests a high degree of sample purity, devoid of significant secondary phases or impurities. 2.2.2. Preparation of nanoparticles Before conducting any experiment, nanoparticle solutions were prepared by adding specific number of NPs in deionized water. In next step, the mixture placed on a shaker for 18 h to ensure initial solution homogeneity. Subsequently, the solution underwent ultrasonication at 300 W for a total of 60 minutes, divided into three 20-minute intervals, to achieve a uniform dispersed solution suitable for further experimental plans. 2.2.3. Surface modification of NPs For surface modification, 2.5 g of VTES was added to 2.5 g of NPs and 150 mL of toluene. Subsequently, the suspension was stirred 12 hours at room temperature. Next, the solution was centrifuged at 3000 rpm for 10 min, and the solid particles were separated. Then, to remove any unreacted modified VTES materials and functionalize the NPs, the obtained sediment was washed with 50 mL of ethanol in a shaker and dried at 70°C for 2 h [ 33 , 34 , 38 – 40 ]. As an example, Fig. 5 shows the reaction schematic of silica modification with VTES. The left side of the picture demonstrates the silica NPs with OH hydroxyl groups, the middle shape is the molecular structure of VTES and modified silica depicted in the right side of the picture. The final modified structure with hydrophobic groups enhances the silica adsorption in lamella, preventing bubble coalescence as well as improving the stability of bubbles during injection process [ 38 – 40 ]. In addition, modified nano-silica with VTES improves the sweep efficiency of porous medium by improved mobility control through apparent gas viscosity reduction. 2.3. Characterization of foam 2.3.1. Measurement of foamability by SDS surfactant Foamability and foam stability were assessed to determine the critical micelle concentration (CMC) of the SDS surfactant. Two methods—visual observation and conductivity measurement were implemented to evaluate the effect of SDS concentration on foam generation. In the visual method, SDS solutions with concentrations ranging from 0.05 to 0.30 wt% were prepared. Each solution was transferred into capped test tubes, shaking uniformly for 15 seconds. The foam height is recorded immediately as an indicator of foamability. In the conductivity method, the CMC of SDS was determined using a laboratory probe to measure changes in conductivity as surfactant concentration increased. Both methods confirmed that the CMC of SDS was 0.236 wt% [ 41 – 43 ]. 2.3.2. Foam stability measurement To evaluate the foam stability (known as static test), the volume reduction of the generated foams with time will be measured [ 29 ]. To end this, 50 mL of the foam-generating solution was transferred into a 250 mL glass cylinder. A sparger (foam generator) was located at the bottom of the cylinder, and the gas flow rate was adjusted using a mass flow controller (MFC) before gas injection into the solution. As the gas enters into the solution, fine bubbles were generated due to the presence of SDS surfactant. Figure 6 illustrates a schematic of the foam stability measurement setup. All experiments were conducted with a gas injection flow rate of 20 mL/min. Gas injection continued until the foam height reached 200 mL. At this point, the gas flow was stopped, and the foam height was recorded every 10 minutes. During this test, foam half-life is reported once the foam volume reaches to 100 mL. The data measurement has been conducted several times to 2.3.3. Micromodel displacement tests The micromodel was constructed using a three-millimeter-thick acrylic glass plate, also known as polymethyl acrylate, and sold under the trade name Plexiglas. Plexiglas exhibits a higher level of transparency, luster, and environmental resistance than normal glass. A noteworthy property of Plexiglas sheets is their impressive resistance to atmospheric agents and UV radiation. Plexiglas exhibits enhanced pressure resistance compared to glass, absorbs minimal moisture, and possesses exceptional tensile strength. We used the Plexiglas micromodel for simulation. The reservoirs were oil-wet, so an oil-wet micromodel was selected for comparison. A new technique was used to construct the micromodel for better understanding and modeling of the surface events in porous media using CorelDRAW® software. As illustrated in Fig. 7 , the blue lines are used for engraving, and black/crimson lines are used for cutting the plate in the software. The pore-throat in the matrix system is 150 µm in width and 290 µm in depth, while the fractures are 800 µm in depth and 1700 µm in width. The optimal stability concentration was determined, and forming solutions for surfactant foam, nanoparticles (NPs), and modified nanoparticles were made after conducting stability experiments. The injection rate of foam into the micromodel was selected 6 ml/min. The reason to choose a flow rate higher than 5 mL/min but lower than 10 mL/min was to ensure that the foam could enter the micromodel. In other words, low flow rate of foam would not be able to enter into the micromodel. In contrary, it is very difficult to evaluate the recovery of porous medium in high flow rate of foam. According to Fig. 8 , the solution with the optimum concentration was added into a graduated cylinder. Then, two pipettes, one for releasing gas and another for injecting foam, were placed inside the micromodel at the end of the cylinder. In the related tests, foam was injected into the micromodel at a flow rate of 6 milliliters per minute (mL/min). As the gas was released from the sparger, foam was generated and removed from the second pipette. After preparing the foam-generating solution, the micromodel was photographed at specified intervals for three minutes. ImageJ was used to analyze the quantity of oil used in the micromodel. 3. Results and discussion 3.1. Characterization of surface-modified SiO 2 nanostructures and stability analysis 3.1.1. Surface modification of SiO 2 nanostructures To confirm the process of surface modification of NPs, standard analysis techniques were implemented, and the results are presented in this section. To end this, FTIR spectroscopy, contact angle measurements, and zeta potential tests were conducted to verify the changes in molecular structure. 3.1.2. FTIR spectrometry Figures 9 –a, 9-b, and 9-c depict the FTIR spectra of SiO 2 , modified SiO 2 , and VTES in the range of 600–4100 cm − 1 . Specific absorption peaks, such as the H-C bond in alkane (at 2925 cm − 1 ), were identified. The stretching vibrations indicate the presence of H-O, N-H, and amine groups in the range of 3100–3700 cm − 1 . In addition, the widths of the peaks are narrow due to the presence of hydrogen bonds. These two strong absorptions occur because of hydroxyl groups and many C-H bonds in the structure of the main components in biomass (lignin, hemicellulose, and cellulose). The wavelength of 1797 cm − 1 is related to Si-O-Si bonds. Additionally, the strong bond at 1088 cm − 1 is related to the Si-O stretching vibration mode, which indicates the effect of VTES on the peak of SiO 2 NPs [ 44 , 45 ]. The Si-O-Si bonds at the wavenumber of 797 cm − 1 reveals the existence of VTES in the molecular structure of NPs. The emergence of aliphatic, C-H, and C-N peaks at 1206, 1655, and 2925 cm − 1 confirms the impact of VTES on alteration of surface property of silica NPs [ 46 , 47 ]. 3.1.3. DLS and zeta potential analysis To evaluate the foam stability, aqueous suspensions containing modified SiO₂ (0.1 wt%) and Al₂O₃ (0.05 wt%) nanoparticles were prepared and analyzed using Dynamic Light Scattering (DLS) technique as well as zeta potential analysis. The results were summarized in Table 2 . As a general conclusion, suspensions of silica and modified SiO₂ nanoparticles showed greater stability than aluminum oxide in ambient temperature after 24 hours. It is beneficial to mention that the presence of VTES as a surface modifier in NPs structure has shifted the value of zeta potential from a large negative value to a significantly positive value, showing the effectiveness of VTES in molecular structure. These results are in great agreement with the previous experimental findings [ 48 ]. In addition, the high absolute values of zeta potential clearly indicate the low agglomeration tendency of the silica NPs solution. Furthermore, the low zeta potential numbers for alumina NPs solution indicates the solution instability as well as high agglomeration tendency. It is worth mentioning that, during the alumina tests, significant particle deposition was observed, confirming the zeta potential results. In this step, it is decided to continue the experimental plan only with the silica nanoparticles due to high alumina solution instability. Table 2 Size and stability characterizations of SiO 2 , Modified SiO 2 , and Al 2 O 3 suspensions in water using DLS and Zeta Potential analysis. Sample Particle size (nm) a Zeta potential (mV) b SiO 2 (0.1wt%) MS SiO 2 (0.1wt%) Al 2 O 3 (0.05wt%) 111.5 208.6 301.1 -58 42.5 -12.8 a Maximum amount of standard deviation: u (mean particle size) = ± 18 nm. b Maximum amount of standard deviation: u (zeta potential) = ± 3 mV 3.1.4. Contact angle analysis To complete the stability tests, contact angle measurements were performed in two separate air-water and oil-water systems. As shown in Table 3 , significant wettability alteration was observed in presence of the modified SiO 2 . Moreover, comparing the contact angle values clearly confirms the profound modification of silica nanoparticle’s structure. Table 3 Results of contact angle measurements in air-water and oil water system for NPs. Contact angles Air-water Oil-water SiO 2 81 \(\:^\circ\:\) 73 \(\:^\circ\:\) Modified Silica (MS) 120 \(\:^\circ\:\) 174 \(\:^\circ\:\) 3.2. Foam Stability Test 3.2.1. Effects of SiO 2 and Modified Silica NPs on foam stability Foam stability was measured in presence of SDS surfactant, silica nanoparticles and modified silica nanoparticles by static tests. Figure 10 presents the foam volume reduction versus time for different mass concentration of SDS surfactant. As can be observed, for all experimental scenarios, addition of SDS shows same increasing trend of foam half-life [ 49 , 50 ]. Moreover, the lowest half time was observed in 0.01 wt% of SDS solution with 36 minutes while the highest half time was recorded in 0.5 wt% of SDS solution with 103 minutes. Furthermore, it is observed that increasing the concentration of SDS from 0.5 wt% to 1 wt% has inverse effect on foam half-life [ 31 , 51 ]. An important factor that influences the foam stability is the effect of increased lamella weight at higher surfactant concentration [ 27 , 30 ]. During foam discharge, the gravitational force leads to a higher lamella weight, causing destruction of the lamella [ 52 – 54 ]. Therefore, the concentration of 0.5 wt% was selected as optimum concentration as well as baseline for the next set of experiments. Figure 11 demonstrates reduction of foam volume against time in optimum SDS concentration with the presence of various mass percent of SiO 2 NPs (0.02, 0.04, 0.06, and 0.1 wt%). Obviously, the same increasing trend was observed for foam half-life and the solution with 0.06-wt% SDS-SiO 2 was recorded as optimum NPs concentration. Moreover, addition of NPs improved the foam half-life from 103 to 126 min at optimum SDS concentration. Obtained results clearly shows the improvement of foam stability in the presence of NPs. Nanoparticle loading into the solution delays foam coalescence since the particles trapped in the bubble’s interface, creating a strong barrier against the foam film thinning [ 55 , 56 ].. In addition, smaller bubbles were observed in this set of experiments, indicating more strong bubble formation [ 57 – 59 ]. Figure 12 illustrates the results of foam stability experiments in the presence of modified nano-silica particles. As could be observed, same increasing trend for foam stability has been demonstrated. It is worth to mention that the highest value for foam stability is recorded with 166 min compared with the previous experimental cases. Based on FTIR analysis, the high hydrophilicity of the NPs can be attributed into the presence of hydroxyl (-OH) group in molecular structure [ 55 , 56 ]. Therefore, the highest foam-stabilizing performance observed by changing the nanoparticle surface from hydrophilic to hydrophobic [ 55 , 60 , 61 ]. Modified silica NPs have the potential to form strong bonds with foam, thereby improving the foam quality [ 17 , 60 ]. In other words, modified nano-silica presence in the interfaces create more strong and thicker layers between the gas and liquid compartments in the foam, causing the highest half-life for generated foams [ 61 ]. 3.2.2. Impact of smart ions on foam stability In order to explore the impact of smart ions on foam stability, a concentration of 0.1 wt% of MgCl₂, K₂SO₄, NaCl, and Na₂SO₄ salts were used. It should be noted that the experiments were performed in optimal SDS solutions containing silica NPs and modified-silica NPs with 0.05 wt% and 0.06 wt% concentrations, respectively. The results were demonstrated in Tables 4 and 5 . In addition to foam half-life values, the percentages of stability reduction have been calculated in the same tables. The results indicate that in all cases, foam half-life has been reduced. The highest foam half-life reduction was occurred for silica NPs and modified-silica NPs using NACL salt with 42.86% and 54.22% reduction, respectively. This results are in great agreement with the previous experimental findings[ 4 ]]. Table 4 Half-life of smart ions formed in the presence of surfactant-NPs (0.06%wt) SiO 2 (MgCl 2 ) SiO 2 (K 2 SO 4 ) SiO 2 (NaCl) SiO 2 (Na 2 SO 4 ) Half-Time (min) 70 80 72 76 % Reduction 44.44 36.51 42.86 39.68 Table 5 Half-life of smart ions formed in the presence of modified surfactant-NPs (0.05%wt) SiO 2 (MgCl 2 ) SiO 2 (K 2 SO 4 ) SiO 2 (NaCl) SiO 2 (Na 2 SO 4 ) Half-Time (min) 77 90 76 80 % Reduction 53.61 45.78 54.22 51.80 3.2.3 Impact of gas flow rate on foam formation and stability In this section, the impact of gas injection flow rates on foam formation and stability was investigated. To end this, gas flow rates is changed ranging from 20 to 100 mL/min. Figures 13 , 14 and 15 show the results of half-life measurements in presence of SDS surfactant, silica nanoparticles and modified silica nanoparticles by static tests. According to the results, the highest stability was recorded at a flow rate of 20 mL/min, while the lowest stability was observed at a flow rate of 90–100 mL/min. Therefore, a flow rate of 20 mL/min was maintained consistently in all subsequent stability experiments. The stability of foam is influenced by a variety of factors, including physical and chemical properties, foam structure, and bladder size. It is concluded that the bubbles with smaller spherical surfaces are more stable than bubbles with larger polygonal shapes [ 22 , 62 ]. To determine optimal concentration of surfactants and NPs, it is crucial to consider the factors that influence the bubble size and foam stability [ 63 ]. It is worth to mention that implementing the optimal operational condition to create gas foams is caused to have formation of smaller bubbles with enhanced stability[ 64 , 65 ]. 3.3. Micromodel flooding tests Dynamic micromodel flooding tests with optimum foam solutions were conducted to compare the recovery percent of CO 2 gas, SDS surfactant, silica nanoparticles and modified silica nanoparticles. The results were demonstrated in Table 6 . Table 6 Results of oil recovery in micromodel tests Injecting fluid type Nanoparticle concentration Inj. rate Ml/min Injection duration (s) Amount of oil extracted (%) CO 2 gas - 6 200 7.91 Surfactant foam - 6 1800 31.33 Silica foam 0.06 6 1800 38.90 Modified silica foam 0.05 6 1800 48.04 According to the results, injection of CO 2 gas inside the micromodel is caused to have very poor sweep efficiency. During the injection process, injected gas has higher mobility ratio compared to in-situ oil, resulting to move in a pore with lower resistance. Therefore, the breakthrough of gas happens very fast, ending with meager oil recovery percent. This phenomenon is confirmed by visual observation in Fig. 16 . Most of the pores in the first flooding tests with pure carbon dioxide gas wasn’t depleted, causing to record very small sweep efficiency in micromodel. In addition, most of the recovered oil is produced from the trapped oil in fractures with higher conductivity. The second phase of injection test is related to the foam injection with optimal SDS concentration. In this step, a significant oil recovery occurred compared to previous flooding test with 31.33 recovery percent. As mentioned in previous sections, foam stability of SDS solution improved, causing higher half-life as well as higher ability to move the oil toward the production end. Additionally, the higher apparent viscosity of injecting fluid is caused to have closer mobility ratio for oil and foam, resulting much higher oil recovery. A snapshot of the micromodel depicted in Fig. 17 , showing the higher depletion area in the micromodel. Finally, the impact of silica nanoparticles and modified silica nanoparticles presence in foam structure were evaluated by running at the same injection rates. The obtained recovery for silica nanoparticles and modified silica nanoparticles was 38.90 and 48.04, respectively. Obviously, higher foam stability with NPs is the main reason for improved sweep efficiency. Additionally, creating more hydrophobic structure with modified NPs is caused to have much stronger bonds with oil, resulting the recovery enhancement by 10 percent. Furthermore, presence of NPs in foam structures enhances the apparent viscosity of injecting fluid, causing to enhance the mobility ratio of present phases in the medium. The obtained results are in great agreement with the pictures of the micromodel, showing much higher depletion rate of porous medium. A snapshot of micromodel with modified NPs as injecting fluid is depicted in Fig. 18 , confirming the obtained higher recovery percent in NPs flooding experiments. As can be observed, the injected fluid in this experiment have been depleted majority of in-situ oil, causing very small remaining oil saturation in micromodel and pores. 4. Conclusions The present study performed experiments to evaluate foamability, foam stability, and recovery enhancement using static and dynamic tests. The foam stability was improved by modifying the surface of silica NPs with VTES. The surface modification was verified using FTIR spectroscopy and measuring contact angles. Furthermore, foam generation and stability were examined using anionic surfactants, silica, aluminum oxide NPs, and a combination of surfactant-NPs, both in the presence and absence of MgCl₂, K₂SO₄, NaCl, and Na₂SO₄ salts. Additionally, NPs increase the apparent viscosity of carbon dioxide gas, block larger pores, and reduce capillary pressure. Ultimately, the foam solution effectively penetrates narrower pores and improves oil displacement. Followings are the main obtained results: For all experimental scenarios, addition of SDS, NPs and modified NPs show same increasing trend of foam half-life as well as stability enhancement. The collapse time for the SDS surfactant foam increased from 103 to 126 min for silica NPs and reaches to 163 min for modified silica NPs. Increasing the concentration of NPs did not necessarily lead to a more stable foam/emulsion. Foam stability can be reduced by the addition of solid particles or surfactants. The presence of NPs in the foam-generating solution increased the foam half-life, and the thickness of the layers reduced the size of the bubbles, causing more stable foam generation. The presence of salts in foam generating solution is caused to reduce the foam half-life . In the micromodel injection tests, carbon dioxide gas and an aqueous liquid containing surfactants were unable to enter the matrix due to the absence of high pressure, resulting in viscous fingering as well as small sweep efficiency. Due to the hydrophilic properties of NPs, when the VTES surface modifier is applied, a part of the hydrophilic silica surface becomes hydrophobic while the remainder maintains its hydrophilic properties. As a result, higher recovery was obtained with more stable foams. Declarations Author Contribution Asena Golmoradi: Conceptualization, Methodology, Validation, Investigation, Writing original Draft, Visualization. Rohallah Hashemi: Conceptualization, Methodology, Data curation, Writing- Reviewing and Editing, Resources, Supervision. Data Availability The datasets generated and/or analyzed during the current study are not publicly available due to privacy concerns regarding patient confidentiality, but are available from the corresponding author on reasonable request. References Liu, Y., K.J.I.J.o, E. & Wang Anal. Influencing Factors Water Flooding Productivity Tight Oil Reservoirs 3 (1): 80–84. (2023). Hamza, A. et al. CO2 enhanced gas recovery and sequestration in depleted gas reservoirs: A review. 196: p. 107685. (2021). AlYousef, Z. et al. Enhancing Stab. foam use Nanopart. 31 (10): 10620–10627. (2017). Nikolova, C. and T.J.F.i.m. Gutierrez, Use of microorganisms in the recovery of oil from recalcitrant oil reservoirs: Current state of knowledge, technological advances and future perspectives . 10 : p. 2996. (2020). Malozyomov, B. V. et al. Overview of methods for enhanced oil recovery from conventional and unconventional reservoirs. 16(13): p. 4907. (2023). Chen, W. et al. A comprehensive review on screening, application, and perspectives of surfactant-based chemical-enhanced oil recovery methods in unconventional oil reservoirs. 37(7): pp. 4729–4750. (2023). Mohammadi, M. H. et al. An Overview of Oil Recovery Techniques: From Primary to Enhanced Oil Recovery Methods. 3(1): pp. 291–301. (2024). Davoodi, S. et al. Compr. Rev. beneficial Appl. viscoelastic surfactants wellbore hydraulic fracturing fluids 338 : 127228. (2023). Worthen, A. J. et al. Nanoparticle-stabilized carbon dioxide-. -water foams fine texture . 391 , 142–151 (2013). Bondor, P. J. E. C. & Management Appl. carbon dioxide enhanced oil recovery 33 (5–8): 579–586. (1992). Sheng, J. & Engineering Enhanced oil recovery shale reservoirs gas injection 22 : 252–259. (2015). Boeije, C. & Rossen, W. SAG foam flooding in carbonate rocks . in IOR 2017-19th European Symposium on Improved Oil Recovery . European Association of Geoscientists & Engineers. (2017). Al-Shargabi, M. et al. Carbon dioxide applications for enhanced oil recovery assisted by nanoparticles: Recent developments . 7 (12): pp. 9984–9994. (2022). Massarweh, O. & Abushaikha, A. S. J. P. A review of recent developments in CO2 mobility control in enhanced oil recovery . 8 (3): pp. 291–317. (2022). Farzaneh, S. A. & Sohrabi, M. A review of the status of foam applications in enhanced oil recovery . in SPE Europec featured at EAGE Conference and Exhibition? SPE. (2013). Yekeen, N. et al. A comprehensive review of experimental studies of nanoparticles-stabilized foam for enhanced oil recovery . 164 : pp. 43–74. (2018). Zhang, Y. et al. Nanoparticles as foam stabilizer: Mechanism, control parameters and application in foam flooding for enhanced oil recovery . 202 : p. 108561. (2021). Massarweh, O. & Abushaikha, A. S. J. E. R. The use of surfactants in enhanced oil recovery: A review of recent advances. 6: pp. 3150–3178. (2020). Ab Rasid, S. A. et al. Rev. parameters affecting Nanopart. stabilized foam Perform. based recent. analyses 208 : 109475. (2022). Rossen, W. R. Foams in enhanced oil recovery, in Foams p. 413–464 (Routledge, 2017). Yu, J. et al. Effect of particle hydrophobicity on CO2 foam generation and foam flow behavior in porous media . 126 : pp. 104–108. (2014). Afifi, H. R. et al. A comprehensive review on critical affecting parameters on foam stability and recent advancements for foam-based EOR scenario. : p. 116808. (2021). Cui, Z. G. et al. Aqueous foams stabilized by in situ surface activation of CaCO3 nanoparticles via adsorption of anionic surfactant . 26 (15): pp. 12567–12574. (2010). Wang, H. et al. Effect of water-soluble polymers on the performance of dust-suppression foams: Wettability, surface viscosity and stability . 568 : pp. 92–98. (2019). Ramsden, W. J. P.o.t.r.S.o.L., Separation of solids in the surface-layers of solutions and ‘suspensions’(observations on surface-membranes, bubbles, emulsions, and mechanical coagulation).—Preliminary account. 72(477–486): pp. 156–164. (1904). Pickering, S. U. & Transactions J.J.o.t.C.S., Cxcvi —emulsions 91 : 2001–2021. (1907). Yekeen, N. et al. Influence of surfactant and electrolyte concentrations on surfactant Adsorption and foaming characteristics . 149 : pp. 612–622. (2017). Guo, F. et al. Stabilization of CO 2 foam using by-product fly ash and recyclable iron oxide nanoparticles to improve carbon utilization in EOR processes . 1 (4): pp. 814–822. (2017). Bayat, A. E. et al. Assessing the effects of nanoparticle type and concentration on the stability of CO2 foams and the performance. enhanced oil recovery . 511 , 222–231 (2016). Simjoo, M. et al. Foam stability in the presence of oil: effect of surfactant concentration and oil type . 438 : pp. 148–158. (2013). Yekeen, N. et al. Synergistic effects of nanoparticles and surfactants on n-decane-water interfacial tension and bulk foam stability at high temperature . 179 : pp. 814–830. (2019). Ma, X. et al. Surface modification and characterization of highly dispersed silica nanoparticles by a cationic surfactant. 358(1–3): pp. 172–176. (2010). Sonn, J. S. et al. Effect of surface modification of silica nanoparticles by silane coupling agent on decontamination foam stability . 114 : pp. 11–18. (2018). Monjezi, K., Mohammadi, M., A.R.J.J.o.M, L. & Khaz'ali Stabilizing CO2 foams using APTES surface-modified nanosilica: Foamability, foaminess, foam stability, and transport in oil-wet fractured porous media. 311: p. 113043. (2020). Lee, J. et al. Effect of surface modification of CaCO3 nanoparticles by a silane coupling agent methyltrimethoxysilane on the stability of foam and emulsion . 74 : pp. 63–70. (2019). Li, X., Pu, C., X.J.J.o.M, L. & Chen Improved foam Stab. through combination silica nanoparticle thixotropic polymer: experimental study 346 : 117153. (2022). Roychand, R. et al. A quantitative study on the effect of nano SiO2, nano Al2O3 and nano CaCO3 on the physicochemical properties of very high volume fly ash cement composite. Eur. J. Environ. Civil Eng. 24 (6), 724–739 (2020). Izadi, M. et al. Effect of poly (amidoamine) dendrimer-grafted silica nanoparticles and different chain extenders on thermal properties of epoxy-modified polyurethane composites. Bull. Mater. Sci. 44 (3), 199 (2021). Mardani, H. et al. Multifunctional poly (amidoamine)-functionalized silica nanoparticles for epoxide-functionalized polyurethane and novolac resins crosslinking. J. Therm. Anal. Calorim. 147 (12), 6679–6687 (2022). Easavinejad, H. et al. Preparation of silica-decorated graphite oxide and epoxy-modified phenolic resin composites. Fullerenes, Nanotubes and Carbon Nanostructures, 30(3): pp. 348–357. (2022). Shojaei, M. J. et al. Combined Eff. Nanopart. surfactants upon foam Stab. 238 : 116601. (2021). Domínguez, A. et al. Determ. Crit. micelle concentration some surfactants three techniques 74 (10): 1227. (1997). Babamahmoudi, S., S.J.J.o.M, L. & Riahi Application of nano particle for enhancement of foam stability in the presence of crude oil: Experimental investigation . 264 : pp. 499–509. (2018). Li, Y., Tingling, Y. & Shiyuan, C. J. A. P. S. Study of nano-silica/fluorinated acrylate copolymer hybrid emulsion and the polymerization kinetics. 2008(3): pp. 221–230. Zhao, F. et al. Preparation and characterization of nano-SiO2/fluorinated polyacrylate composite latex via nano-SiO2/acrylate dispersion. 396: pp. 328–335. (2012). Zhuang, J. et al. Observation of potential contaminants in processed biomass using fourier transform infrared spectroscopy . 10 (12): p. 4345. (2020). Vahur, S. et al. ATR-FT-IR spectral collection of conservation materials in the extended region of 4000-80 cm–1. 408: pp. 3373–3379. (2016). Bhattacharjee, S. DLS and zeta potential–what they are and what they are not? J. Controlled Release . 235 , 337–351 (2016). Emami, H. et al. Experimental investigation of foam flooding using anionic and nonionic surfactants: A screening scenario to assess the effects of salinity and ph on foam stability and foam height . 7 (17): pp. 14832–14847. (2022). Farhadi, H. et al. Experimental study of nanoparticle-surfactant-stabilized CO2 foam: Stability and mobility control . 111 : pp. 449–460. (2016). Bello, A. et al. Enhancing N2 and CO2 foam stability by surfactants and nanoparticles at high temperature and various salinities . 215 : p. 110720. (2022). Kulkarni, A. A. & Joshi, J. B. J. I. and e.c. research, Bubble formation and bubble rise velocity in gas – liquid systems: a review. 44(16): pp. 5873–5931. (2005). Wang, H. et al. Regulation of bubble size in flotation: A review . 8 (5): p. 104070. (2020). Baz-Rodríguez, S. A. et al. Effect of electrolytes in aqueous solutions on oxygen transfer in gas–liquid bubble columns . 92 (11): pp. 2352–2360. (2014). Guerrini, L., Alvarez-Puebla, R. A. & Pazos-Perez, N. J. M. Surf. modifications Nanopart. Stab. Biol. fluids 11 (7): 1154. (2018). Ngouangna, E. N. et al. Surface modification of nanoparticles to improve oil recovery Mechanisms: A critical review of the methods, influencing Parameters, advances and prospects. 360: p. 119502. (2022). Singh, R., Mohanty, K. K. J. E. & Fuels Synergy between Nanopart. surfactants stabilizing foams oil recovery 29 (2): 467–479. (2015). Ahmadi, A. et al. Nano-stabilized foam for enhanced oil recovery using green nanocomposites and anionic surfactants: An experimental study . 290 : p. 130201. (2024). Monjezi, K., Mohammadi, M. & Khaz'ali, A. R. Stabilizing CO2 foams using APTES surface-modified nanosilica: Foamability, foaminess, foam stability, and transport in oil-wet fractured porous media. J. Mol. Liq. 311 , 113043 (2020). Sun, Q. et al. Aqueous foam stabilized by partially hydrophobic nanoparticles in the presence of surfactant . 471 : pp. 54–64. (2015). Saeedi Dehaghani, A. H., Gharibshahi, R. & Mohammadi, M. J. S. R. Utilization of synthesized silane-based silica Janus nanoparticles to improve foam stability applicable in oil production: static study . 13 (1): p. 18652. (2023). Schramm, L. L., K.J.J.o.P, S., Mannhardt & Engineering The effect of wettability on foam sensitivity to crude oil in porous media . 15 (1): pp. 101–113. (1996). Wang, H. et al. Experimental investigation of the mechanism of foaming agent concentration affecting foam stability . 20 (6): pp. 1443–1451. (2017). Lesov, I. et al. Factors controlling formation Stab. foams used as precursors porous Mater. 426 : 9–21. (2014). Behnammotlagh, M. A., Hashemi, R., Rizi, T., Mohammadtaheri, Z., Mohammadi, M. & M., and Experimental Study of the Effect of the Combined Monoethylene Glycol with NaCl/CaCl 2 Salts on Sour Gas Hydrate Inhibition with Low-Concentration Hydrogen Sulfide. J. Chem. Eng. Data . 67 (5), 1250–1258 (2022). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 10 Oct, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 24 Jul, 2025 Reviews received at journal 23 Jul, 2025 Reviews received at journal 23 Jul, 2025 Reviewers agreed at journal 16 Jul, 2025 Reviewers agreed at journal 15 Jul, 2025 Reviewers agreed at journal 29 May, 2025 Reviewers agreed at journal 25 May, 2025 Reviewers invited by journal 15 May, 2025 Editor assigned by journal 15 May, 2025 Editor invited by journal 12 May, 2025 Submission checks completed at journal 12 May, 2025 First submitted to journal 25 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6530385","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":457117513,"identity":"4f584501-0456-46e0-be3a-d283b1f63055","order_by":0,"name":"Asena Golmoradi","email":"","orcid":"","institution":"Isfahan University of Technology","correspondingAuthor":false,"prefix":"","firstName":"Asena","middleName":"","lastName":"Golmoradi","suffix":""},{"id":457117514,"identity":"77fbf1fe-7b0a-41e2-92ec-cafd4dbbd47b","order_by":1,"name":"Rohallah Hashemi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAw0lEQVRIiWNgGAWjYDACCQYGZiDFw88MFWAjWotkMwNjA0laGAwOQLUQBOazmx9/LqjYJmN8nMf8AUONHQOf9AH8WmTuHDOTnnHmNo/ZYR7DBoZjyQxsfAkE3CWRYMbM2wbTwnaAgY2HkFck0j9/5v13m8e4GaTlH1FacgykeRtu8xgwA7UwthGnpUya59htHonDbIUzEvuSeYhx2ObPPDW37fn7D2/48OGbnZx8DwEtqCABGKckaRgFo2AUjIJRgB0AALFzNQglXbC/AAAAAElFTkSuQmCC","orcid":"","institution":"Isfahan University of Technology","correspondingAuthor":true,"prefix":"","firstName":"Rohallah","middleName":"","lastName":"Hashemi","suffix":""}],"badges":[],"createdAt":"2025-04-25 15:53:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6530385/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6530385/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-025-19355-2","type":"published","date":"2025-10-10T15:57:19+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":83146660,"identity":"e315b26b-24fe-4114-8a15-647835660edd","added_by":"auto","created_at":"2025-05-20 13:08:24","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":365345,"visible":true,"origin":"","legend":"\u003cp\u003eFESEM images of SiO\u003csub\u003e2\u003c/sub\u003e \u003cstrong\u003eNPs\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/3a33630ea4a69a904284b388.png"},{"id":83146661,"identity":"23e53f0c-784d-451c-a1bd-3eac603d4c0c","added_by":"auto","created_at":"2025-05-20 13:08:24","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":315219,"visible":true,"origin":"","legend":"\u003cp\u003eFESEM images of Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e \u003cstrong\u003eNPs.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/58c88aa773a7fabbfb8cfab1.png"},{"id":83147402,"identity":"f155c5d0-93db-4e1f-ba3d-2302bdcc5aee","added_by":"auto","created_at":"2025-05-20 13:16:24","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":33746,"visible":true,"origin":"","legend":"\u003cp\u003eXRD patterns of SiO\u003csub\u003e2\u003c/sub\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/45ef6bbd44012c5e0a336ece.png"},{"id":83145822,"identity":"971bc4dc-542c-48da-beee-75f0f8125f0a","added_by":"auto","created_at":"2025-05-20 13:00:24","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":36498,"visible":true,"origin":"","legend":"\u003cp\u003eXRD patterns of Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/e34c1edd9716a80f7f73c83c.png"},{"id":83149126,"identity":"b4b8578d-b005-43cf-91d2-4ace3a04cfce","added_by":"auto","created_at":"2025-05-20 13:32:24","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":59250,"visible":true,"origin":"","legend":"\u003cp\u003eReaction schematic of silica modification with VTES\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/8da5122aa3203cfbd7da813e.png"},{"id":83148533,"identity":"0aaf03f4-9404-4f20-a653-f4ccc56145e9","added_by":"auto","created_at":"2025-05-20 13:24:24","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":149776,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic of the setup for measuring foam stability.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/4c49996be39654a5a9231ad6.png"},{"id":83147401,"identity":"18291f4c-5bf1-4731-a349-5140e4b50beb","added_by":"auto","created_at":"2025-05-20 13:16:24","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":214185,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic of the micromodel pattern.\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/30ad2658b2903c1e314ba523.png"},{"id":83146666,"identity":"df19f119-e05c-42ca-a97a-eef17b3f32bc","added_by":"auto","created_at":"2025-05-20 13:08:24","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":74852,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic of the micromodel\u003cstrong\u003e \u003c/strong\u003efor foam injection in the micromodel\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/b18be9cfb69f7656401c24b7.png"},{"id":83145838,"identity":"3ec98c09-0077-490c-a891-9b17d207b264","added_by":"auto","created_at":"2025-05-20 13:00:24","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":87834,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR spectra of (a) untreated SiO\u003csub\u003e2\u003c/sub\u003e, (b) VTES-treated SiO\u003csub\u003e2\u003c/sub\u003e NPs, and (c) VTES surface modifier\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/64e861273a7a3a24cb0845e5.png"},{"id":83146664,"identity":"12311278-6aa7-461a-b4bb-0f0bdd083ba3","added_by":"auto","created_at":"2025-05-20 13:08:24","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":48045,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eChange of foam height versus time for optimal concentration of SDS surfactant.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/d46c01d13223dfeb7023439f.png"},{"id":83145833,"identity":"10c6c62d-b5ee-4259-8d28-c41480c7aa07","added_by":"auto","created_at":"2025-05-20 13:00:24","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":43032,"visible":true,"origin":"","legend":"\u003cp\u003eStability of foam at the optimal concentration of silica NPs in the presence of surfactant.\u003c/p\u003e","description":"","filename":"11.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/2d79ea01e0f6c7945170f40d.png"},{"id":83145829,"identity":"6f98dad0-33dd-42ff-86d0-5bf06970e0f3","added_by":"auto","created_at":"2025-05-20 13:00:24","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":63848,"visible":true,"origin":"","legend":"\u003cp\u003eStability of surfactant foam at different concentrations of modified nano-silica.\u003c/p\u003e","description":"","filename":"12.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/fed4a293b74e52045462338d.png"},{"id":83145846,"identity":"19048c74-8f8d-41cb-849b-76210456bf1a","added_by":"auto","created_at":"2025-05-20 13:00:24","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":243159,"visible":true,"origin":"","legend":"\u003cp\u003eFESEM images related to the formation time and half-life of the foams formed at flow rates of 20, 30, and 40 ml/min.\u003c/p\u003e","description":"","filename":"13.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/3082902a5616233a12d71387.png"},{"id":83145850,"identity":"96a5813b-fd8a-4b56-a522-49baa35a0c24","added_by":"auto","created_at":"2025-05-20 13:00:24","extension":"png","order_by":14,"title":"Figure 14","display":"","copyAsset":false,"role":"figure","size":207650,"visible":true,"origin":"","legend":"\u003cp\u003eFESEM images related to the formation time and half-life of the foams formed at flow rates of 50, 60, and 70 ml/min .\u003c/p\u003e","description":"","filename":"14.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/c5c7b801762580d750f1364d.png"},{"id":83145881,"identity":"ca18b0dd-3813-40ef-b4b4-8b60a67e01d4","added_by":"auto","created_at":"2025-05-20 13:00:25","extension":"png","order_by":15,"title":"Figure 15","display":"","copyAsset":false,"role":"figure","size":224828,"visible":true,"origin":"","legend":"\u003cp\u003eFESEM images related to the formation time and half-life of the foams formed at flow rates of 80, 90, and 100 ml/min.\u003c/p\u003e","description":"","filename":"15.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/a437e647afc1878c7d5da778.png"},{"id":83146671,"identity":"fceb53a6-5e2d-4a47-b5e1-ffaf258094ab","added_by":"auto","created_at":"2025-05-20 13:08:24","extension":"png","order_by":16,"title":"Figure 16","display":"","copyAsset":false,"role":"figure","size":213521,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic of micromodel during pure gas injection.\u003c/p\u003e","description":"","filename":"16.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/43341bd62e552661b531c080.png"},{"id":83147403,"identity":"746c2bf2-80cb-46fc-9059-65eccf154bb1","added_by":"auto","created_at":"2025-05-20 13:16:24","extension":"png","order_by":17,"title":"Figure 17","display":"","copyAsset":false,"role":"figure","size":212601,"visible":true,"origin":"","legend":"\u003cp\u003eA schematic of micromodel during foam injection process with optimal SDS concentration.\u003c/p\u003e","description":"","filename":"17.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/2eda3cfba01ae3cbe0e1854a.png"},{"id":83145862,"identity":"494973d6-2c22-4f56-8ad0-40d6e1e6e54e","added_by":"auto","created_at":"2025-05-20 13:00:25","extension":"png","order_by":18,"title":"Figure 18","display":"","copyAsset":false,"role":"figure","size":207362,"visible":true,"origin":"","legend":"\u003cp\u003eA schematic of micromodel during Modified NPs injection process with optimal SDS concentration.\u003c/p\u003e","description":"","filename":"18.png","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/467d601e832bcad28e98099a.png"},{"id":93419659,"identity":"656e2a54-450f-4585-be5e-1db7d3ddda24","added_by":"auto","created_at":"2025-10-13 16:05:26","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4215070,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6530385/v1/c18ea32e-a9e2-48ca-8e48-8f4160a2d097.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eExperimental study of nanoparticle-stabilized foam with VTES surface modifier on generation, foamability, stability and oil recovery enhancement\u003c/p\u003e","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eOil extraction from hydrocarbon reservoirs is carried out using primary, secondary, and tertiary recovery techniques, tailored to the specific characteristics of each reservoir. However, primary and secondary methods typically manage to recover approximately 30\u0026ndash;50% of the oil in a typical oil reservoir [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Enhanced oil recovery (EOR) techniques, including chemical and gas injection, microbial extraction, and thermal extraction, modify the physical and chemical properties of brine/surfactant/crude oil systems, such as interfacial tension (IFT), viscosity, and wettability [\u003cspan additionalcitationids=\"CR5 CR6\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. As an EOR techniques, Carbon dioxide injection into hydrocarbon reservoirs has recently become a promising and effective technique due to its non-toxic, non-polar, and non-flammable nature [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Although CO\u003csub\u003e2\u003c/sub\u003e injection into oil reservoirs is reasonably efficient, there exists still challenges including low sweep efficiency, gravity segregation, and unfavorable mobility of injecting fluid [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. As a replacement to mitigate the challenges of gas injection, the use of other methods besides CO\u003csub\u003e2\u003c/sub\u003e injection is of crucial importance for sweep efficiency enhancement [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Foams are considered as a promising method to overcome the disadvantages of CO\u003csub\u003e2\u003c/sub\u003e injection, enhancing the oil recovery, improving the sweep efficiency as well as reducing the viscous fingering of high-permeability zones [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. In addition, to improve the quality of injected foams and maintaining lamella\u0026rsquo;s stability, surfactants mixtures, which are also known as surface-active agents, are used in enhancing the stability of foam films[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In practical implementation, previous studies indicated that the injection of surfactant-containing foam into a porous medium under reservoir conditions could negatively affect foam stability and lead to lamella thinning [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Nanoparticles (NPs) as foam stabilizer with surfactants has garnered the attention of many researchers due to meager absorption into the rock surface, [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. In previous studies, researchers have investigated the effects of surfactants, NPs, modified NPs, polymers, brine, temperature, and pressure on the stability of foams composed of different components [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Despite the numerous studies in this research area, more studies are still required to fill the quite significant gap between the understanding and application of foam in field operations.\u003c/p\u003e \u003cp\u003eRamsden in 1903 and Pickering in 1907 introduced an innovative method for stabilizing foam emulsions through the use of NPs, which proved to be both cost-effective and efficient in foam generation [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Considering the low absorption of anionic surfactant molecules and silica NPs on the surfaces of sandstone reservoir rocks, the reason for using silica NPs and anionic surfactants was to achieve good foam stability [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. The effects of aluminum oxide, titanium oxide, copper oxide, and SiO\u003csub\u003e2\u003c/sub\u003e NPs were examined. Among these NPs, SiO\u003csub\u003e2\u003c/sub\u003e can better improve the stability of foams in the presence of carbon dioxide [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. As Simjoo et al. found, foams can remain stable in oil-free and oil-containing environments using diverse commercial surfactants, such as Petrostep SB, Dowfax 8390, C12-15 Enordet, and C14-16 α-olefin sulfonate (AOS). These authors produced foams using the mentioned surfactants without pure alkanes. In the absence of oil, Petrostep SB was the most stable surfactant, whereas AOS exhibited the longest foam longevity when oil was present [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Yekeen et al. confirmed that a surfactant in combination with NPs, particularly with nano-SiO\u003csub\u003e2\u003c/sub\u003e, is more effective than Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e in improving foam stability [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. In comparison with surfactants, NPs are less likely to adhere to clay minerals and reservoir rocks during migration. Furthermore, by modifying the surface of NPs, the stability and quality of the foam can be improved due to the silanol group on the surface [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. Dimethyldichlorosilane (DMDCS) was used for surface modification of silica NPs, and it was found that the hydrophobicity of the modified silica (MS) NPs results in the highest foam stability compared to the unmodified silica [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Monjezi et al. used modified nanoparticle structures 3-aminopropyltriethoxysilane (APTES) and found that surface modification changes the silica surface, making the NPs more oil-wet (gas-wet) in the oil-water (air-water) system [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Lee et al. reported surface modification of calcium carbonate NPs by methyltrimethoxysilane (MTMS). The formation of large and spherical emulsion droplets with high and low concentrations of MTMS was a result of this work. Additionally, most of the CaCO\u003csub\u003e3\u003c/sub\u003e was surrounded by bubbles, which improved the stability of the foam [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. A new foam system with a long half-life and a large foam volume was achieved using hydrophobic SiO\u003csub\u003e2\u003c/sub\u003e NPs and sodium dodecyl benzene sulfonate (SDBS) under reservoir conditions. Furthermore, using foam flooding, this system enhanced oil recovery [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe present study investigates the foam generation quality of sodium dodecyl sulfate (SDS) surfactant as a base case scenario. Subsequently, the same procedure will be implemented using silica nano-particle to observe the alteration in foam properties. In addition, the stability of combined SDS surfactant with modified nano-silica using VTES surface modifier were examined since it has not been previously explored in the literatures. Furthermore, the quality of foam was investigated in more severe condition in presence of varying salinities. Finally, a polymethyl-methacrylate (PMMA) micromodel was used to evaluate the recovery enhancement in different gas and foam injection scenarios.\u003c/p\u003e"},{"header":"2. Experimental","content":"\u003ch3\u003e2. 1. Materials\u003c/h3\u003e\n\u003cp\u003eSodium dodecyl sulfate (SDS) with a purity of \u0026ge;\u0026thinsp;98.0% and a molecular weight of 288.38 g/mol was used as the foaming agent. Aluminum oxide (Al₂O₃) and silicon dioxide (SiO₂) nanoparticles (NPs) were obtained from US Research Nanomaterials Inc., and their detailed specifications are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eTriethoxyvinylsilane (VTES), magnesium chloride (MgCl₂), potassium sulfate (K₂SO₄), sodium chloride (NaCl), and sodium sulfate (Na₂SO₄), each with a purity of \u0026ge;\u0026thinsp;98.0%, were procured from Merck Chemical Company (Darmstadt, Germany). Carbon dioxide gas, used for foam generation, was supplied by Parsan Gas Company (Isfahan, Iran). Crude oil, with a density of 0.89 g/mL and a viscosity of 30.2 cp at 25\u0026deg;C, was obtained from an oil reservoir located in southwestern Iran. All experiments were conducted using deionized water to ensure consistency and minimize impurities.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eChemical and physical properties of studied NPs\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNanoparticle form\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSize (nm)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDensity\u003c/p\u003e \u003cp\u003e[g/cm\u003csup\u003e3\u003c/sup\u003e]\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSpecific surface area [m\u003csup\u003e2\u003c/sup\u003eg]\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSilicon dioxide\u003c/p\u003e \u003cp\u003e)SiO\u003csub\u003e2\u003c/sub\u003e(\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSpherical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20\u0026ndash;30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e260\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAluminum oxide (Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNearly spherical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u0026ndash;20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e340\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003e2. 2. Methods\u003c/h3\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.2.1. Characterization of Silica and Aluminum Oxide Nanoparticles\u003c/h2\u003e \u003cp\u003e The SiO\u003csub\u003e2\u003c/sub\u003e and Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e NPs were characterized through X-ray diffraction and field-emission scanning electron microscopy (FE-SEM). The diameters of silica and aluminum oxide NPs are approximately in the ranges of 20\u0026ndash;30 nm and 50\u0026ndash;200 nm, respectively, and the results can be observed in Figs.\u0026nbsp;1 and 2. It should be noted that some particle sizes were demonstrated in both pictures. It is clear that there exists agglomeration of NPs in the presented images.\u003c/p\u003e\u003cp\u003eThe XRD analysis of SiO\u003csub\u003e2\u003c/sub\u003e and Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e was demonstrated in Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e3\u003c/span\u003e, \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e4\u003c/span\u003e. As shown, a broad peak at 22\u0026deg; (2-Theta) is characteristic of amorphous silica, indicating the absence of long-range crystalline order. Conversely, the XRD pattern of crystalline Al₂O₃ exhibits distinct peaks, corresponding to specific crystallographic planes. For the alumina nanoparticles (NPs), the pattern clearly displays multiple sharp and intense peaks, confirming the crystalline nature of the Al₂O₃ nanoparticles. The positions of these sharp peaks align with standard reference patterns for γ-Al₂O₃ (gamma phase) [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Notably, the absence of additional peaks suggests a high degree of sample purity, devoid of significant secondary phases or impurities.\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003e2.2.2. Preparation of nanoparticles\u003c/h2\u003e \u003cp\u003eBefore conducting any experiment, nanoparticle solutions were prepared by adding specific number of NPs in deionized water. In next step, the mixture placed on a shaker for 18 h to ensure initial solution homogeneity. Subsequently, the solution underwent ultrasonication at 300 W for a total of 60 minutes, divided into three 20-minute intervals, to achieve a uniform dispersed solution suitable for further experimental plans.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003e2.2.3. Surface modification of NPs\u003c/h2\u003e \u003cp\u003eFor surface modification, 2.5 g of VTES was added to 2.5 g of NPs and 150 mL of toluene. Subsequently, the suspension was stirred 12 hours at room temperature. Next, the solution was centrifuged at 3000 rpm for 10 min, and the solid particles were separated. Then, to remove any unreacted modified VTES materials and functionalize the NPs, the obtained sediment was washed with 50 mL of ethanol in a shaker and dried at 70\u0026deg;C for 2 h [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan additionalcitationids=\"CR39\" citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. As an example, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e5\u003c/span\u003e shows the reaction schematic of silica modification with VTES. The left side of the picture demonstrates the silica NPs with OH hydroxyl groups, the middle shape is the molecular structure of VTES and modified silica depicted in the right side of the picture. The final modified structure with hydrophobic groups enhances the silica adsorption in lamella, preventing bubble coalescence as well as improving the stability of bubbles during injection process [\u003cspan additionalcitationids=\"CR39\" citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. In addition, modified nano-silica with VTES improves the sweep efficiency of porous medium by improved mobility control through apparent gas viscosity reduction.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Characterization of foam\u003c/h2\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e2.3.1. Measurement of foamability by SDS surfactant\u003c/h2\u003e \u003cp\u003eFoamability and foam stability were assessed to determine the critical micelle concentration (CMC) of the SDS surfactant. Two methods\u0026mdash;visual observation and conductivity measurement were implemented to evaluate the effect of SDS concentration on foam generation.\u003c/p\u003e \u003cp\u003eIn the visual method, SDS solutions with concentrations ranging from 0.05 to 0.30 wt% were prepared. Each solution was transferred into capped test tubes, shaking uniformly for 15 seconds. The foam height is recorded immediately as an indicator of foamability.\u003c/p\u003e \u003cp\u003eIn the conductivity method, the CMC of SDS was determined using a laboratory probe to measure changes in conductivity as surfactant concentration increased. Both methods confirmed that the CMC of SDS was 0.236 wt% [\u003cspan additionalcitationids=\"CR42\" citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003e2.3.2. Foam stability measurement\u003c/h2\u003e \u003cp\u003eTo evaluate the foam stability (known as static test), the volume reduction of the generated foams with time will be measured [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. To end this, 50 mL of the foam-generating solution was transferred into a 250 mL glass cylinder. A sparger (foam generator) was located at the bottom of the cylinder, and the gas flow rate was adjusted using a mass flow controller (MFC) before gas injection into the solution. As the gas enters into the solution, fine bubbles were generated due to the presence of SDS surfactant. Figure\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e6\u003c/span\u003e illustrates a schematic of the foam stability measurement setup. All experiments were conducted with a gas injection flow rate of 20 mL/min. Gas injection continued until the foam height reached 200 mL. At this point, the gas flow was stopped, and the foam height was recorded every 10 minutes. During this test, foam half-life is reported once the foam volume reaches to 100 mL. The data measurement has been conducted several times to\u003c/p\u003e\u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e \u003ch2\u003e2.3.3. Micromodel displacement tests\u003c/h2\u003e \u003cp\u003eThe micromodel was constructed using a three-millimeter-thick acrylic glass plate, also known as polymethyl acrylate, and sold under the trade name Plexiglas. Plexiglas exhibits a higher level of transparency, luster, and environmental resistance than normal glass. A noteworthy property of Plexiglas sheets is their impressive resistance to atmospheric agents and UV radiation. Plexiglas exhibits enhanced pressure resistance compared to glass, absorbs minimal moisture, and possesses exceptional tensile strength. We used the Plexiglas micromodel for simulation. The reservoirs were oil-wet, so an oil-wet micromodel was selected for comparison. A new technique was used to construct the micromodel for better understanding and modeling of the surface events in porous media using CorelDRAW\u0026reg; software. As illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e7\u003c/span\u003e, the blue lines are used for engraving, and black/crimson lines are used for cutting the plate in the software. The pore-throat in the matrix system is 150 \u0026micro;m in width and 290 \u0026micro;m in depth, while the fractures are 800 \u0026micro;m in depth and 1700 \u0026micro;m in width.\u003c/p\u003e \u003cp\u003eThe optimal stability concentration was determined, and forming solutions for surfactant foam, nanoparticles (NPs), and modified nanoparticles were made after conducting stability experiments. The injection rate of foam into the micromodel was selected 6 ml/min. The reason to choose a flow rate higher than 5 mL/min but lower than 10 mL/min was to ensure that the foam could enter the micromodel. In other words, low flow rate of foam would not be able to enter into the micromodel. In contrary, it is very difficult to evaluate the recovery of porous medium in high flow rate of foam.\u003c/p\u003e \u003cp\u003eAccording to Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e8\u003c/span\u003e, the solution with the optimum concentration was added into a graduated cylinder. Then, two pipettes, one for releasing gas and another for injecting foam, were placed inside the micromodel at the end of the cylinder. In the related tests, foam was injected into the micromodel at a flow rate of 6 milliliters per minute (mL/min). As the gas was released from the sparger, foam was generated and removed from the second pipette. After preparing the foam-generating solution, the micromodel was photographed at specified intervals for three minutes. ImageJ was used to analyze the quantity of oil used in the micromodel.\u003c/p\u003e\u003c/div\u003e \u003c/div\u003e"},{"header":"3. Results and discussion","content":"\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Characterization of surface-modified SiO\u003csub\u003e2\u003c/sub\u003e nanostructures and stability analysis\u003c/h2\u003e \u003cdiv id=\"Sec14\" class=\"Section3\"\u003e \u003ch2\u003e3.1.1. Surface modification of SiO\u003csub\u003e2\u003c/sub\u003e nanostructures\u003c/h2\u003e \u003cp\u003eTo confirm the process of surface modification of NPs, standard analysis techniques were implemented, and the results are presented in this section. To end this, FTIR spectroscopy, contact angle measurements, and zeta potential tests were conducted to verify the changes in molecular structure.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section3\"\u003e \u003ch2\u003e3.1.2. FTIR spectrometry\u003c/h2\u003e \u003cp\u003eFigures \u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e9\u003c/span\u003e \u0026ndash;a, 9-b, and 9-c depict the FTIR spectra of SiO\u003csub\u003e2\u003c/sub\u003e, modified SiO\u003csub\u003e2\u003c/sub\u003e, and VTES in the range of 600\u0026ndash;4100 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Specific absorption peaks, such as the H-C bond in alkane (at 2925 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), were identified. The stretching vibrations indicate the presence of H-O, N-H, and amine groups in the range of 3100\u0026ndash;3700 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. In addition, the widths of the peaks are narrow due to the presence of hydrogen bonds. These two strong absorptions occur because of hydroxyl groups and many C-H bonds in the structure of the main components in biomass (lignin, hemicellulose, and cellulose). The wavelength of 1797 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e is related to Si-O-Si bonds. Additionally, the strong bond at 1088 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e is related to the Si-O stretching vibration mode, which indicates the effect of VTES on the peak of SiO\u003csub\u003e2\u003c/sub\u003e NPs [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. The Si-O-Si bonds at the wavenumber of 797 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e reveals the existence of VTES in the molecular structure of NPs. The emergence of aliphatic, C-H, and C-N peaks at 1206, 1655, and 2925 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e confirms the impact of VTES on alteration of surface property of silica NPs [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e, \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section3\"\u003e \u003ch2\u003e3.1.3. DLS and zeta potential analysis\u003c/h2\u003e \u003cp\u003eTo evaluate the foam stability, aqueous suspensions containing modified SiO₂ (0.1 wt%) and Al₂O₃ (0.05 wt%) nanoparticles were prepared and analyzed using Dynamic Light Scattering (DLS) technique as well as zeta potential analysis. The results were summarized in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. As a general conclusion, suspensions of silica and modified SiO₂ nanoparticles showed greater stability than aluminum oxide in ambient temperature after 24 hours. It is beneficial to mention that the presence of VTES as a surface modifier in NPs structure has shifted the value of zeta potential from a large negative value to a significantly positive value, showing the effectiveness of VTES in molecular structure. These results are in great agreement with the previous experimental findings [\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e]. In addition, the high absolute values of zeta potential clearly indicate the low agglomeration tendency of the silica NPs solution. Furthermore, the low zeta potential numbers for alumina NPs solution indicates the solution instability as well as high agglomeration tendency. It is worth mentioning that, during the alumina tests, significant particle deposition was observed, confirming the zeta potential results. In this step, it is decided to continue the experimental plan only with the silica nanoparticles due to high alumina solution instability.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSize and stability characterizations of SiO\u003csub\u003e2\u003c/sub\u003e, Modified SiO\u003csub\u003e2\u003c/sub\u003e, and Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e suspensions in water using DLS and Zeta Potential analysis.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eParticle size (nm)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eZeta potential (mV)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e (0.1wt%)\u003c/p\u003e \u003cp\u003eMS SiO\u003csub\u003e2\u003c/sub\u003e (0.1wt%)\u003c/p\u003e \u003cp\u003eAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e (0.05wt%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e111.5\u003c/p\u003e \u003cp\u003e208.6\u003c/p\u003e \u003cp\u003e301.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-58\u003c/p\u003e \u003cp\u003e42.5\u003c/p\u003e \u003cp\u003e-12.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003ea Maximum amount of standard deviation: u (mean particle size)\u0026thinsp;=\u0026thinsp;\u0026plusmn;\u0026thinsp;18 nm. b Maximum amount of standard deviation: u (zeta potential)\u0026thinsp;=\u0026thinsp;\u0026plusmn;\u0026thinsp;3 mV\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section3\"\u003e \u003ch2\u003e3.1.4. Contact angle analysis\u003c/h2\u003e \u003cp\u003eTo complete the stability tests, contact angle measurements were performed in two separate air-water and oil-water systems. As shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, significant wettability alteration was observed in presence of the modified SiO\u003csub\u003e2\u003c/sub\u003e. Moreover, comparing the contact angle values clearly confirms the profound modification of silica nanoparticle\u0026rsquo;s structure.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of contact angle measurements in air-water and oil water system for NPs.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eContact angles\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAir-water\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOil-water\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e81\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:^\\circ\\:\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e73\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:^\\circ\\:\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eModified Silica (MS)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e120\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:^\\circ\\:\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e174\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:^\\circ\\:\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Foam Stability Test\u003c/h2\u003e \u003cdiv id=\"Sec19\" class=\"Section3\"\u003e \u003ch2\u003e3.2.1. Effects of SiO\u003csub\u003e2\u003c/sub\u003e and Modified Silica NPs on foam stability\u003c/h2\u003e \u003cp\u003eFoam stability was measured in presence of SDS surfactant, silica nanoparticles and modified silica nanoparticles by static tests. Figure\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e10\u003c/span\u003e presents the foam volume reduction versus time for different mass concentration of SDS surfactant. As can be observed, for all experimental scenarios, addition of SDS shows same increasing trend of foam half-life [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e, \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e]. Moreover, the lowest half time was observed in 0.01 wt% of SDS solution with 36 minutes while the highest half time was recorded in 0.5 wt% of SDS solution with 103 minutes.\u003c/p\u003e \u003cp\u003eFurthermore, it is observed that increasing the concentration of SDS from 0.5 wt% to 1 wt% has inverse effect on foam half-life [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e]. An important factor that influences the foam stability is the effect of increased lamella weight at higher surfactant concentration [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. During foam discharge, the gravitational force leads to a higher lamella weight, causing destruction of the lamella [\u003cspan additionalcitationids=\"CR53\" citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e]. Therefore, the concentration of 0.5 wt% was selected as optimum concentration as well as baseline for the next set of experiments.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e11\u003c/span\u003e demonstrates reduction of foam volume against time in optimum SDS concentration with the presence of various mass percent of SiO\u003csub\u003e2\u003c/sub\u003e NPs (0.02, 0.04, 0.06, and 0.1 wt%). Obviously, the same increasing trend was observed for foam half-life and the solution with 0.06-wt% SDS-SiO\u003csub\u003e2\u003c/sub\u003e was recorded as optimum NPs concentration. Moreover, addition of NPs improved the foam half-life from 103 to 126 min at optimum SDS concentration.\u003c/p\u003e \u003cp\u003eObtained results clearly shows the improvement of foam stability in the presence of NPs. Nanoparticle loading into the solution delays foam coalescence since the particles trapped in the bubble\u0026rsquo;s interface, creating a strong barrier against the foam film thinning [\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e, \u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e].. In addition, smaller bubbles were observed in this set of experiments, indicating more strong bubble formation [\u003cspan additionalcitationids=\"CR58\" citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e12\u003c/span\u003e illustrates the results of foam stability experiments in the presence of modified nano-silica particles. As could be observed, same increasing trend for foam stability has been demonstrated. It is worth to mention that the highest value for foam stability is recorded with 166 min compared with the previous experimental cases. Based on FTIR analysis, the high hydrophilicity of the NPs can be attributed into the presence of hydroxyl (-OH) group in molecular structure [\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e, \u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e]. Therefore, the highest foam-stabilizing performance observed by changing the nanoparticle surface from hydrophilic to hydrophobic [\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e, \u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e, \u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e]. Modified silica NPs have the potential to form strong bonds with foam, thereby improving the foam quality [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e]. In other words, modified nano-silica presence in the interfaces create more strong and thicker layers between the gas and liquid compartments in the foam, causing the highest half-life for generated foams [\u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section3\"\u003e \u003ch2\u003e3.2.2. Impact of smart ions on foam stability\u003c/h2\u003e \u003cp\u003eIn order to explore the impact of smart ions on foam stability, a concentration of 0.1 wt% of MgCl₂, K₂SO₄, NaCl, and Na₂SO₄ salts were used. It should be noted that the experiments were performed in optimal SDS solutions containing silica NPs and modified-silica NPs with 0.05 wt% and 0.06 wt% concentrations, respectively. The results were demonstrated in Tables\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e and \u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. In addition to foam half-life values, the percentages of stability reduction have been calculated in the same tables. The results indicate that in all cases, foam half-life has been reduced. The highest foam half-life reduction was occurred for silica NPs and modified-silica NPs using NACL salt with 42.86% and 54.22% reduction, respectively.\u003c/p\u003e \u003cp\u003eThis results are in great agreement with the previous experimental findings[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]].\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eHalf-life of smart ions formed in the presence of surfactant-NPs (0.06%wt)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e (MgCl\u003csub\u003e2\u003c/sub\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e (K\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e (NaCl)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e(Na\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHalf-Time (min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e76\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e% Reduction\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e44.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e42.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e39.68\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eHalf-life of smart ions formed in the presence of modified surfactant-NPs (0.05%wt)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e (MgCl\u003csub\u003e2\u003c/sub\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e (K\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e (NaCl)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e(Na\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHalf-Time (min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e% Reduction\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e53.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e54.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e51.80\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec21\" class=\"Section3\"\u003e \u003ch2\u003e3.2.3 Impact of gas flow rate on foam formation and stability\u003c/h2\u003e \u003cp\u003eIn this section, the impact of gas injection flow rates on foam formation and stability was investigated. To end this, gas flow rates is changed ranging from 20 to 100 mL/min. Figures\u0026nbsp;\u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e13\u003c/span\u003e, \u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e14\u003c/span\u003e and 15 show the results of half-life measurements in presence of SDS surfactant, silica nanoparticles and modified silica nanoparticles by static tests.\u003c/p\u003e \u003cp\u003eAccording to the results, the highest stability was recorded at a flow rate of 20 mL/min, while the lowest stability was observed at a flow rate of 90\u0026ndash;100 mL/min. Therefore, a flow rate of 20 mL/min was maintained consistently in all subsequent stability experiments. The stability of foam is influenced by a variety of factors, including physical and chemical properties, foam structure, and bladder size. It is concluded that the bubbles with smaller spherical surfaces are more stable than bubbles with larger polygonal shapes [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e]. To determine optimal concentration of surfactants and NPs, it is crucial to consider the factors that influence the bubble size and foam stability [\u003cspan citationid=\"CR63\" class=\"CitationRef\"\u003e63\u003c/span\u003e]. It is worth to mention that implementing the optimal operational condition to create gas foams is caused to have formation of smaller bubbles with enhanced stability[\u003cspan citationid=\"CR64\" class=\"CitationRef\"\u003e64\u003c/span\u003e, \u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e65\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec22\" class=\"Section2\"\u003e \u003ch2\u003e3.3. Micromodel flooding tests\u003c/h2\u003e \u003cp\u003eDynamic micromodel flooding tests with optimum foam solutions were conducted to compare the recovery percent of CO\u003csub\u003e2\u003c/sub\u003e gas, SDS surfactant, silica nanoparticles and modified silica nanoparticles. The results were demonstrated in Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of oil recovery in micromodel tests\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInjecting fluid\u003c/p\u003e \u003cp\u003etype\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNanoparticle concentration\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInj. rate\u003c/p\u003e \u003cp\u003eMl/min\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eInjection duration (s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eAmount of oil extracted (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003e gas\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e7.91\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurfactant foam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e31.33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSilica foam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e38.90\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eModified silica foam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e48.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAccording to the results, injection of CO\u003csub\u003e2\u003c/sub\u003e gas inside the micromodel is caused to have very poor sweep efficiency. During the injection process, injected gas has higher mobility ratio compared to in-situ oil, resulting to move in a pore with lower resistance. Therefore, the breakthrough of gas happens very fast, ending with meager oil recovery percent. This phenomenon is confirmed by visual observation in Fig.\u0026nbsp;\u003cspan refid=\"Fig13\" class=\"InternalRef\"\u003e16\u003c/span\u003e. Most of the pores in the first flooding tests with pure carbon dioxide gas wasn\u0026rsquo;t depleted, causing to record very small sweep efficiency in micromodel. In addition, most of the recovered oil is produced from the trapped oil in fractures with higher conductivity.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe second phase of injection test is related to the foam injection with optimal SDS concentration. In this step, a significant oil recovery occurred compared to previous flooding test with 31.33 recovery percent. As mentioned in previous sections, foam stability of SDS solution improved, causing higher half-life as well as higher ability to move the oil toward the production end. Additionally, the higher apparent viscosity of injecting fluid is caused to have closer mobility ratio for oil and foam, resulting much higher oil recovery. A snapshot of the micromodel depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig14\" class=\"InternalRef\"\u003e17\u003c/span\u003e, showing the higher depletion area in the micromodel.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFinally, the impact of silica nanoparticles and modified silica nanoparticles presence in foam structure were evaluated by running at the same injection rates. The obtained recovery for silica nanoparticles and modified silica nanoparticles was 38.90 and 48.04, respectively. Obviously, higher foam stability with NPs is the main reason for improved sweep efficiency. Additionally, creating more hydrophobic structure with modified NPs is caused to have much stronger bonds with oil, resulting the recovery enhancement by 10 percent. Furthermore, presence of NPs in foam structures enhances the apparent viscosity of injecting fluid, causing to enhance the mobility ratio of present phases in the medium. The obtained results are in great agreement with the pictures of the micromodel, showing much higher depletion rate of porous medium. A snapshot of micromodel with modified NPs as injecting fluid is depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig15\" class=\"InternalRef\"\u003e18\u003c/span\u003e, confirming the obtained higher recovery percent in NPs flooding experiments. As can be observed, the injected fluid in this experiment have been depleted majority of in-situ oil, causing very small remaining oil saturation in micromodel and pores.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eThe present study performed experiments to evaluate foamability, foam stability, and recovery enhancement using static and dynamic tests. The foam stability was improved by modifying the surface of silica NPs with VTES. The surface modification was verified using FTIR spectroscopy and measuring contact angles. Furthermore, foam generation and stability were examined using anionic surfactants, silica, aluminum oxide NPs, and a combination of surfactant-NPs, both in the presence and absence of MgCl₂, K₂SO₄, NaCl, and Na₂SO₄ salts. Additionally, NPs increase the apparent viscosity of carbon dioxide gas, block larger pores, and reduce capillary pressure. Ultimately, the foam solution effectively penetrates narrower pores and improves oil displacement. Followings are the main obtained results:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eFor all experimental scenarios, addition of SDS, NPs and modified NPs show same increasing trend of foam half-life as well as stability enhancement.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eThe collapse time for the SDS surfactant foam increased from 103 to 126 min for silica NPs and reaches to 163 min for modified silica NPs.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eIncreasing the concentration of NPs did not necessarily lead to a more stable foam/emulsion. Foam stability can be reduced by the addition of solid particles or surfactants.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eThe presence of NPs in the foam-generating solution increased the foam half-life, and the thickness of the layers reduced the size of the bubbles, causing more stable foam generation.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eThe presence of salts in foam generating solution is caused to reduce the foam half-life .\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eIn the micromodel injection tests, carbon dioxide gas and an aqueous liquid containing surfactants were unable to enter the matrix due to the absence of high pressure, resulting in viscous fingering as well as small sweep efficiency.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eDue to the hydrophilic properties of NPs, when the VTES surface modifier is applied, a part of the hydrophilic silica surface becomes hydrophobic while the remainder maintains its hydrophilic properties. As a result, higher recovery was obtained with more stable foams.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAsena Golmoradi: Conceptualization, Methodology, Validation, Investigation, Writing original Draft, Visualization. Rohallah Hashemi: Conceptualization, Methodology, Data curation, Writing- Reviewing and Editing, Resources, Supervision.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets generated and/or analyzed during the current study are not publicly available due to privacy concerns regarding patient confidentiality, but are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLiu, Y., K.J.I.J.o, E. \u0026amp; Wang \u003cem\u003eAnal. Influencing Factors Water Flooding Productivity Tight Oil Reservoirs\u003c/em\u003e \u003cb\u003e3\u003c/b\u003e(1): 80\u0026ndash;84. (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHamza, A. et al. \u003cem\u003eCO2 enhanced gas recovery and sequestration in depleted gas reservoirs: A review.\u003c/em\u003e 196: p. 107685. (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlYousef, Z. et al. \u003cem\u003eEnhancing Stab. foam use Nanopart.\u003c/em\u003e \u003cb\u003e31\u003c/b\u003e(10): 10620\u0026ndash;10627. (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNikolova, C. and T.J.F.i.m. Gutierrez, \u003cem\u003eUse of microorganisms in the recovery of oil from recalcitrant oil reservoirs: Current state of knowledge, technological advances and future perspectives\u003c/em\u003e. \u003cb\u003e10\u003c/b\u003e: p. 2996. (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMalozyomov, B. V. et al. \u003cem\u003eOverview of methods for enhanced oil recovery from conventional and unconventional reservoirs.\u003c/em\u003e 16(13): p. 4907. (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen, W. et al. \u003cem\u003eA comprehensive review on screening, application, and perspectives of surfactant-based chemical-enhanced oil recovery methods in unconventional oil reservoirs.\u003c/em\u003e 37(7): pp. 4729\u0026ndash;4750. (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMohammadi, M. H. et al. \u003cem\u003eAn Overview of Oil Recovery Techniques: From Primary to Enhanced Oil Recovery Methods.\u003c/em\u003e 3(1): pp. 291\u0026ndash;301. (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDavoodi, S. et al. \u003cem\u003eCompr. Rev. beneficial Appl. viscoelastic surfactants wellbore hydraulic fracturing fluids\u003c/em\u003e \u003cb\u003e338\u003c/b\u003e: 127228. (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWorthen, A. J. et al. Nanoparticle-stabilized carbon dioxide-. \u003cem\u003e-water foams fine texture\u003c/em\u003e. \u003cb\u003e391\u003c/b\u003e, 142\u0026ndash;151 (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBondor, P. J. E. C. \u0026amp; Management \u003cem\u003eAppl. carbon dioxide enhanced oil recovery\u003c/em\u003e \u003cb\u003e33\u003c/b\u003e(5\u0026ndash;8): 579\u0026ndash;586. (1992).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSheng, J. \u0026amp; Engineering \u003cem\u003eEnhanced oil recovery shale reservoirs gas injection\u003c/em\u003e \u003cb\u003e22\u003c/b\u003e: 252\u0026ndash;259. (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBoeije, C. \u0026amp; Rossen, W. \u003cem\u003eSAG foam flooding in carbonate rocks\u003c/em\u003e. in \u003cem\u003eIOR 2017-19th European Symposium on Improved Oil Recovery\u003c/em\u003e. European Association of Geoscientists \u0026amp; Engineers. (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAl-Shargabi, M. et al. \u003cem\u003eCarbon dioxide applications for enhanced oil recovery assisted by nanoparticles: Recent developments\u003c/em\u003e. \u003cb\u003e7\u003c/b\u003e(12): pp. 9984\u0026ndash;9994. (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMassarweh, O. \u0026amp; Abushaikha, A. S. J. P. \u003cem\u003eA review of recent developments in CO2 mobility control in enhanced oil recovery\u003c/em\u003e. \u003cb\u003e8\u003c/b\u003e(3): pp. 291\u0026ndash;317. (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFarzaneh, S. A. \u0026amp; Sohrabi, M. \u003cem\u003eA review of the status of foam applications in enhanced oil recovery\u003c/em\u003e. in \u003cem\u003eSPE Europec featured at EAGE Conference and Exhibition?\u003c/em\u003e SPE. (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYekeen, N. et al. \u003cem\u003eA comprehensive review of experimental studies of nanoparticles-stabilized foam for enhanced oil recovery\u003c/em\u003e. \u003cb\u003e164\u003c/b\u003e: pp. 43\u0026ndash;74. (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang, Y. et al. \u003cem\u003eNanoparticles as foam stabilizer: Mechanism, control parameters and application in foam flooding for enhanced oil recovery\u003c/em\u003e. \u003cb\u003e202\u003c/b\u003e: p. 108561. (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMassarweh, O. \u0026amp; Abushaikha, A. S. J. E. R. \u003cem\u003eThe use of surfactants in enhanced oil recovery: A review of recent advances.\u003c/em\u003e 6: pp. 3150\u0026ndash;3178. (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAb Rasid, S. A. et al. \u003cem\u003eRev. parameters affecting Nanopart. stabilized foam Perform. based recent. analyses\u003c/em\u003e \u003cb\u003e208\u003c/b\u003e: 109475. (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRossen, W. R. \u003cem\u003eFoams in enhanced oil recovery, in Foams\u003c/em\u003ep. 413\u0026ndash;464 (Routledge, 2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYu, J. et al. \u003cem\u003eEffect of particle hydrophobicity on CO2 foam generation and foam flow behavior in porous media\u003c/em\u003e. \u003cb\u003e126\u003c/b\u003e: pp. 104\u0026ndash;108. (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAfifi, H. R. et al. \u003cem\u003eA comprehensive review on critical affecting parameters on foam stability and recent advancements for foam-based EOR scenario.\u003c/em\u003e : p. 116808. (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCui, Z. G. et al. \u003cem\u003eAqueous foams stabilized by in situ surface activation of CaCO3 nanoparticles via adsorption of anionic surfactant\u003c/em\u003e. \u003cb\u003e26\u003c/b\u003e(15): pp. 12567\u0026ndash;12574. (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, H. et al. \u003cem\u003eEffect of water-soluble polymers on the performance of dust-suppression foams: Wettability, surface viscosity and stability\u003c/em\u003e. \u003cb\u003e568\u003c/b\u003e: pp. 92\u0026ndash;98. (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRamsden, W. J. P.o.t.r.S.o.L., \u003cem\u003eSeparation of solids in the surface-layers of solutions and \u0026lsquo;suspensions\u0026rsquo;(observations on surface-membranes, bubbles, emulsions, and mechanical coagulation).\u0026mdash;Preliminary account.\u003c/em\u003e 72(477\u0026ndash;486): pp. 156\u0026ndash;164. (1904).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePickering, S. U. \u0026amp; Transactions J.J.o.t.C.S., \u003cem\u003eCxcvi \u0026mdash;emulsions\u003c/em\u003e \u003cb\u003e91\u003c/b\u003e: 2001\u0026ndash;2021. (1907).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYekeen, N. et al. \u003cem\u003eInfluence of surfactant and electrolyte concentrations on surfactant Adsorption and foaming characteristics\u003c/em\u003e. \u003cb\u003e149\u003c/b\u003e: pp. 612\u0026ndash;622. (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuo, F. et al. \u003cem\u003eStabilization of CO 2 foam using by-product fly ash and recyclable iron oxide nanoparticles to improve carbon utilization in EOR processes\u003c/em\u003e. \u003cb\u003e1\u003c/b\u003e(4): pp. 814\u0026ndash;822. (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBayat, A. E. et al. Assessing the effects of nanoparticle type and concentration on the stability of CO2 foams and the performance. \u003cem\u003eenhanced oil recovery\u003c/em\u003e. \u003cb\u003e511\u003c/b\u003e, 222\u0026ndash;231 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSimjoo, M. et al. \u003cem\u003eFoam stability in the presence of oil: effect of surfactant concentration and oil type\u003c/em\u003e. \u003cb\u003e438\u003c/b\u003e: pp. 148\u0026ndash;158. (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYekeen, N. et al. \u003cem\u003eSynergistic effects of nanoparticles and surfactants on n-decane-water interfacial tension and bulk foam stability at high temperature\u003c/em\u003e. \u003cb\u003e179\u003c/b\u003e: pp. 814\u0026ndash;830. (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMa, X. et al. \u003cem\u003eSurface modification and characterization of highly dispersed silica nanoparticles by a cationic surfactant.\u003c/em\u003e 358(1\u0026ndash;3): pp. 172\u0026ndash;176. (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSonn, J. S. et al. \u003cem\u003eEffect of surface modification of silica nanoparticles by silane coupling agent on decontamination foam stability\u003c/em\u003e. \u003cb\u003e114\u003c/b\u003e: pp. 11\u0026ndash;18. (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMonjezi, K., Mohammadi, M., A.R.J.J.o.M, L. \u0026amp; Khaz'ali \u003cem\u003eStabilizing CO2 foams using APTES surface-modified nanosilica: Foamability, foaminess, foam stability, and transport in oil-wet fractured porous media.\u003c/em\u003e 311: p. 113043. (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee, J. et al. \u003cem\u003eEffect of surface modification of CaCO3 nanoparticles by a silane coupling agent methyltrimethoxysilane on the stability of foam and emulsion\u003c/em\u003e. \u003cb\u003e74\u003c/b\u003e: pp. 63\u0026ndash;70. (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi, X., Pu, C., X.J.J.o.M, L. \u0026amp; Chen \u003cem\u003eImproved foam Stab. through combination silica nanoparticle thixotropic polymer: experimental study\u003c/em\u003e \u003cb\u003e346\u003c/b\u003e: 117153. (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRoychand, R. et al. A quantitative study on the effect of nano SiO2, nano Al2O3 and nano CaCO3 on the physicochemical properties of very high volume fly ash cement composite. \u003cem\u003eEur. J. Environ. Civil Eng.\u003c/em\u003e \u003cb\u003e24\u003c/b\u003e (6), 724\u0026ndash;739 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIzadi, M. et al. Effect of poly (amidoamine) dendrimer-grafted silica nanoparticles and different chain extenders on thermal properties of epoxy-modified polyurethane composites. \u003cem\u003eBull. Mater. Sci.\u003c/em\u003e \u003cb\u003e44\u003c/b\u003e (3), 199 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMardani, H. et al. Multifunctional poly (amidoamine)-functionalized silica nanoparticles for epoxide-functionalized polyurethane and novolac resins crosslinking. \u003cem\u003eJ. Therm. Anal. Calorim.\u003c/em\u003e \u003cb\u003e147\u003c/b\u003e (12), 6679\u0026ndash;6687 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEasavinejad, H. et al. \u003cem\u003ePreparation of silica-decorated graphite oxide and epoxy-modified phenolic resin composites.\u003c/em\u003e Fullerenes, Nanotubes and Carbon Nanostructures, 30(3): pp. 348\u0026ndash;357. (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShojaei, M. J. et al. \u003cem\u003eCombined Eff. Nanopart. surfactants upon foam Stab.\u003c/em\u003e \u003cb\u003e238\u003c/b\u003e: 116601. (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDom\u0026iacute;nguez, A. et al. \u003cem\u003eDeterm. Crit. micelle concentration some surfactants three techniques\u003c/em\u003e \u003cb\u003e74\u003c/b\u003e(10): 1227. (1997).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBabamahmoudi, S., S.J.J.o.M, L. \u0026amp; Riahi \u003cem\u003eApplication of nano particle for enhancement of foam stability in the presence of crude oil: Experimental investigation\u003c/em\u003e. \u003cb\u003e264\u003c/b\u003e: pp. 499\u0026ndash;509. (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi, Y., Tingling, Y. \u0026amp; Shiyuan, C. J. A. P. S. \u003cem\u003eStudy of nano-silica/fluorinated acrylate copolymer hybrid emulsion and the polymerization kinetics.\u003c/em\u003e 2008(3): pp. 221\u0026ndash;230.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao, F. et al. \u003cem\u003ePreparation and characterization of nano-SiO2/fluorinated polyacrylate composite latex via nano-SiO2/acrylate dispersion.\u003c/em\u003e 396: pp. 328\u0026ndash;335. (2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhuang, J. et al. \u003cem\u003eObservation of potential contaminants in processed biomass using fourier transform infrared spectroscopy\u003c/em\u003e. \u003cb\u003e10\u003c/b\u003e(12): p. 4345. (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVahur, S. et al. \u003cem\u003eATR-FT-IR spectral collection of conservation materials in the extended region of 4000-80 cm\u0026ndash;1.\u003c/em\u003e 408: pp. 3373\u0026ndash;3379. (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBhattacharjee, S. DLS and zeta potential\u0026ndash;what they are and what they are not? \u003cem\u003eJ. Controlled Release\u003c/em\u003e. \u003cb\u003e235\u003c/b\u003e, 337\u0026ndash;351 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEmami, H. et al. \u003cem\u003eExperimental investigation of foam flooding using anionic and nonionic surfactants: A screening scenario to assess the effects of salinity and ph on foam stability and foam height\u003c/em\u003e. \u003cb\u003e7\u003c/b\u003e(17): pp. 14832\u0026ndash;14847. (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFarhadi, H. et al. \u003cem\u003eExperimental study of nanoparticle-surfactant-stabilized CO2 foam: Stability and mobility control\u003c/em\u003e. \u003cb\u003e111\u003c/b\u003e: pp. 449\u0026ndash;460. (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBello, A. et al. \u003cem\u003eEnhancing N2 and CO2 foam stability by surfactants and nanoparticles at high temperature and various salinities\u003c/em\u003e. \u003cb\u003e215\u003c/b\u003e: p. 110720. (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKulkarni, A. A. \u0026amp; Joshi, J. B. J. I. and e.c. research, \u003cem\u003eBubble formation and bubble rise velocity in gas\u0026thinsp;\u0026ndash;\u0026thinsp;liquid systems: a review.\u003c/em\u003e 44(16): pp. 5873\u0026ndash;5931. (2005).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, H. et al. \u003cem\u003eRegulation of bubble size in flotation: A review\u003c/em\u003e. \u003cb\u003e8\u003c/b\u003e(5): p. 104070. (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBaz-Rodr\u0026iacute;guez, S. A. et al. \u003cem\u003eEffect of electrolytes in aqueous solutions on oxygen transfer in gas\u0026ndash;liquid bubble columns\u003c/em\u003e. \u003cb\u003e92\u003c/b\u003e(11): pp. 2352\u0026ndash;2360. (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuerrini, L., Alvarez-Puebla, R. A. \u0026amp; Pazos-Perez, N. J. M. \u003cem\u003eSurf. modifications Nanopart. Stab. Biol. fluids\u003c/em\u003e \u003cb\u003e11\u003c/b\u003e(7): 1154. (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNgouangna, E. N. et al. \u003cem\u003eSurface modification of nanoparticles to improve oil recovery Mechanisms: A critical review of the methods, influencing Parameters, advances and prospects.\u003c/em\u003e 360: p. 119502. (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSingh, R., Mohanty, K. K. J. E. \u0026amp; Fuels \u003cem\u003eSynergy between Nanopart. surfactants stabilizing foams oil recovery\u003c/em\u003e \u003cb\u003e29\u003c/b\u003e(2): 467\u0026ndash;479. (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAhmadi, A. et al. \u003cem\u003eNano-stabilized foam for enhanced oil recovery using green nanocomposites and anionic surfactants: An experimental study\u003c/em\u003e. \u003cb\u003e290\u003c/b\u003e: p. 130201. (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMonjezi, K., Mohammadi, M. \u0026amp; Khaz'ali, A. R. Stabilizing CO2 foams using APTES surface-modified nanosilica: Foamability, foaminess, foam stability, and transport in oil-wet fractured porous media. \u003cem\u003eJ. Mol. Liq.\u003c/em\u003e \u003cb\u003e311\u003c/b\u003e, 113043 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSun, Q. et al. \u003cem\u003eAqueous foam stabilized by partially hydrophobic nanoparticles in the presence of surfactant\u003c/em\u003e. \u003cb\u003e471\u003c/b\u003e: pp. 54\u0026ndash;64. (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSaeedi Dehaghani, A. H., Gharibshahi, R. \u0026amp; Mohammadi, M. J. S. R. \u003cem\u003eUtilization of synthesized silane-based silica Janus nanoparticles to improve foam stability applicable in oil production: static study\u003c/em\u003e. \u003cb\u003e13\u003c/b\u003e(1): p. 18652. (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchramm, L. L., K.J.J.o.P, S., Mannhardt \u0026amp; Engineering \u003cem\u003eThe effect of wettability on foam sensitivity to crude oil in porous media\u003c/em\u003e. \u003cb\u003e15\u003c/b\u003e(1): pp. 101\u0026ndash;113. (1996).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, H. et al. \u003cem\u003eExperimental investigation of the mechanism of foaming agent concentration affecting foam stability\u003c/em\u003e. \u003cb\u003e20\u003c/b\u003e(6): pp. 1443\u0026ndash;1451. (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLesov, I. et al. \u003cem\u003eFactors controlling formation Stab. foams used as precursors porous Mater.\u003c/em\u003e \u003cb\u003e426\u003c/b\u003e: 9\u0026ndash;21. (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBehnammotlagh, M. A., Hashemi, R., Rizi, T., Mohammadtaheri, Z., Mohammadi, M. \u0026amp; M., and Experimental Study of the Effect of the Combined Monoethylene Glycol with NaCl/CaCl\u003csub\u003e2\u003c/sub\u003e Salts on Sour Gas Hydrate Inhibition with Low-Concentration Hydrogen Sulfide. \u003cem\u003eJ. Chem. Eng. Data\u003c/em\u003e. \u003cb\u003e67\u003c/b\u003e (5), 1250\u0026ndash;1258 (2022).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"foam, surfactant, nanoparticles, foam stability, surface modification, micromodel","lastPublishedDoi":"10.21203/rs.3.rs-6530385/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6530385/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eGas injection in hydrocarbon reservoirs faces challenges, such as low macroscopic sweep efficiency and poor mobility control due to the low density and viscosity of injected gases, leading to gas fingering and gravity segregation. These problems can be resolved by injection of gas as foam to enhance gas mobility as well as sweep efficiency. However, during the foam injection in hydrocarbon reservoirs, foam stability is a crucial factor to enhance the recovery of the process, which could be improved by nanoparticles. Motivated by this interest, the present study aims to generate and stabilize foam with varying nanoparticle concentrations (0.02 to 0.1 wt%) in combination with a 0.236 wt% SDS surfactant, both in the presence and absence of MgCl₂, K₂SO₄, NaCl, and Na₂SO₄ salts. Techniques such as Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), and Dynamic Light Scattering (DLS) confirm successful NP surface modification. The use of vinyltriethoxysilane (VTES) for nanoparticle surface modification increased foam stability. Additionally, micromodel flooding experiments were conducted, and the results were analyzed to assess the transport properties of the fracture-matrix and the oil recovery characteristics of injection materials, including carbon dioxide gas, SDS solutions, and foams stabilized by silica nanoparticles. According to the findings, the surface modification of silica with VTES results in enhancement of foam stability by 30% increase in foam stability experiments. Furthermore, in comparison with pure SDS foam as base case scenario, adding nano-silica and modified nano-silica into solution caused stability enhancement by 22.3% and 61.1%, accordingly. It should be noted that foam stability was negatively affected by an average of 40\u0026ndash;50% in presence of smart ions. In addition, micromodel flooding tests confirmed that surfactant foam containing modified nano-silica achieved the highest oil recovery (48.04%) compared to pure surfactant foam with (31.33%) oil recovery.\u003c/p\u003e","manuscriptTitle":"Experimental study of nanoparticle-stabilized foam with VTES surface modifier on generation, foamability, stability and oil recovery enhancement","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-20 13:00:19","doi":"10.21203/rs.3.rs-6530385/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-07-24T04:47:20+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-24T00:14:42+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-23T11:20:03+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"273280065583182740018039344573834197962","date":"2025-07-16T13:42:02+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"187095395756092245638205750195431019352","date":"2025-07-15T07:31:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"169873833023923271672710347935986310423","date":"2025-05-29T06:17:38+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"164123686157552794965048395527671696999","date":"2025-05-25T12:20:31+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-05-15T13:13:53+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-05-15T13:09:53+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-05-12T08:32:42+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-05-12T05:31:56+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-04-25T15:49:03+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"08554865-2b83-488e-9600-fc1c5659da64","owner":[],"postedDate":"May 20th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":48749922,"name":"Physical sciences/Engineering/Chemical engineering"},{"id":48749923,"name":"Physical sciences/Nanoscience and technology"}],"tags":[],"updatedAt":"2025-10-13T16:00:11+00:00","versionOfRecord":{"articleIdentity":"rs-6530385","link":"https://doi.org/10.1038/s41598-025-19355-2","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-10-10 15:57:19","publishedOnDateReadable":"October 10th, 2025"},"versionCreatedAt":"2025-05-20 13:00:19","video":"","vorDoi":"10.1038/s41598-025-19355-2","vorDoiUrl":"https://doi.org/10.1038/s41598-025-19355-2","workflowStages":[]},"version":"v1","identity":"rs-6530385","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6530385","identity":"rs-6530385","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}