Numerical Evaluation of CO₂, Water, and Combined CO₂–Water Injection for Enhanced Oil Recovery and Carbon Storage in Shale Reservoirs

Numerical Evaluation of CO₂, Water, and Combined CO₂–Water Injection for Enhanced Oil Recovery and Carbon Storage in Shale Reservoirs | 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 Research Article Numerical Evaluation of CO₂, Water, and Combined CO₂–Water Injection for Enhanced Oil Recovery and Carbon Storage in Shale Reservoirs Bin Liu, Zijian Shen, Chao Zhang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7185551/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Under the global carbon neutrality goal, achieving synergistic benefits between enhanced oil recovery and geological CO₂ sequestration in shale reservoirs is of great significance. In this study, we constructed a numerical simulation model based on the geological settings of the Jiyang Depression in the Shengli Oilfield to investigate the performance of three injection strategies: water injection, CO₂ injection, and combined CO₂–water injection. The simulations evaluated the evolution of reservoir pressure, oil saturation, CO₂ saturation, and water saturation over time. Results show that CO₂ injection offers the highest oil recovery and carbon storage potential, while co-injection exhibits a balance between injection stability and displacement efficiency. Compared with previous studies, this work provides a systematic and comparative analysis of multi-scheme injection performance, offering new insights into the optimization of EOR strategies and carbon storage in shale formations. The findings contribute to the theoretical foundation for the efficient development of unconventional resources under low-carbon constraints. Shale oil reservoir CO₂-EOR Numerical simulation Water–CO₂ co-injection Oil recovery efficiency CCUS Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Full Text Additional Declarations No competing interests reported. Tables 1 to 3 are available in the Supplementary Files section. Supplementary Files Tables.docx Cite Share Download PDF Status: Posted Version 1 posted 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. 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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-7185551","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":496464488,"identity":"7da92e79-58de-4e03-9604-1005d4cc637d","order_by":0,"name":"Bin Liu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAxElEQVRIiWNgGAWjYBACPmYGNoYEMJP5wIEPP4jQwobQwpZ4cGYPMVrACAx4jA9zsOFVDNXCzmP24OGOO3LmEjkfDjPwMMjzix0g5DAec4PEM8+MLWfkbjhcYMFgOHN2AkEtZhKJbYcTN9wAapnBw5BgcJtILfUbbuQ8OMzDRoKWBIMbOQzEamErNwBqMdzZ88wAGMgShP3Cz39428OfbYflzdmTH3/48MNGnl+agBY4MIBQEkQqR9IyCkbBKBgFowATAACxAUDiteYzcQAAAABJRU5ErkJggg==","orcid":"","institution":"Northeast Petroleum University","correspondingAuthor":true,"prefix":"","firstName":"Bin","middleName":"","lastName":"Liu","suffix":""},{"id":496464489,"identity":"8a0f85e3-343d-4d74-9935-c700a4f60399","order_by":1,"name":"Zijian Shen","email":"","orcid":"","institution":"Northeast Petroleum University","correspondingAuthor":false,"prefix":"","firstName":"Zijian","middleName":"","lastName":"Shen","suffix":""},{"id":496464490,"identity":"07b9e707-73b0-41cf-a8e5-a802cab73369","order_by":2,"name":"Chao Zhang","email":"","orcid":"","institution":"Modern Education Technique Center, Northeast Petroleum University","correspondingAuthor":false,"prefix":"","firstName":"Chao","middleName":"","lastName":"Zhang","suffix":""}],"badges":[],"createdAt":"2025-07-22 09:53:45","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7185551/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7185551/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88598825,"identity":"26e4611a-fff1-43d9-9d93-0d382f44aee1","added_by":"auto","created_at":"2025-08-08 07:31:29","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":152664,"visible":true,"origin":"","legend":"\u003cp\u003eGeological feature map\u003c/p\u003e","description":"","filename":"Fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1/6c3a10e4fa34f75c97fc7369.png"},{"id":88598831,"identity":"7af0d9f1-f2fc-4b1e-a11c-8f121b544e61","added_by":"auto","created_at":"2025-08-08 07:31:30","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":35870,"visible":true,"origin":"","legend":"\u003cp\u003eSpace discretization and geometry data in the integral finite difference method.\u003c/p\u003e","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1/bcb9e54a512c699c7af9d213.png"},{"id":88600035,"identity":"782a0282-5e8e-4bf9-9768-cafffbab23df","added_by":"auto","created_at":"2025-08-08 07:39:31","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":62433,"visible":true,"origin":"","legend":"\u003cp\u003eFive-point well layout conceptual model and multiple interacting continua\u003c/p\u003e","description":"","filename":"Fig3.png","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1/26c896ae7d284d20d1982c39.png"},{"id":88598833,"identity":"13003361-2576-4d3d-8368-b241e80612d1","added_by":"auto","created_at":"2025-08-08 07:31:31","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":87735,"visible":true,"origin":"","legend":"\u003cp\u003eDiscretized Grid Model\u003c/p\u003e","description":"","filename":"Fig4.png","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1/d92cfe9aea3e33bab8990ab2.png"},{"id":88598860,"identity":"52672dc5-4f02-4d83-8428-2844502dd7e4","added_by":"auto","created_at":"2025-08-08 07:31:34","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":110337,"visible":true,"origin":"","legend":"\u003cp\u003erelative permeability and capillary pressure curves\u003c/p\u003e","description":"","filename":"Fig5.png","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1/5c67088696ca1a27c3cf686c.png"},{"id":88598850,"identity":"074ea78b-260b-4a9e-b45f-ff688e9b7216","added_by":"auto","created_at":"2025-08-08 07:31:33","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":604418,"visible":true,"origin":"","legend":"\u003cp\u003eTemporal evolution of reservoir pressure distribution under different injection strategies: (a–c) after 1 year, (d–f) after 3 years, and (g–i) after 5 years. Injection methods: water injection (a, d, g), CO₂ injection (b, e, h), and CO₂–water co-injection (c, f, i).\u003c/p\u003e","description":"","filename":"Fig6.png","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1/2b9bb40ce3ea8fb272494564.png"},{"id":88601674,"identity":"09fdda91-9a5d-4d53-ad89-53078cb8abe4","added_by":"auto","created_at":"2025-08-08 07:55:30","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":628060,"visible":true,"origin":"","legend":"\u003cp\u003eTemporal evolution of CO₂ saturation distribution under different injection schemes: (a–c) after 1 \u0026nbsp;\u0026nbsp;year, (d–f) after 3 years, and (g–i) after 5 years. Injection methods: water \u0026nbsp;\u0026nbsp;injection (a, d, g), CO₂ injection (b, e, h), and CO₂–water co-injection (c, \u0026nbsp;\u0026nbsp;f, i).\u003c/p\u003e","description":"","filename":"Fig7.png","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1/c7576b7ee62b7ca6a43037c4.png"},{"id":88600050,"identity":"e1140910-af82-4e5f-989e-ff62c8f85a43","added_by":"auto","created_at":"2025-08-08 07:39:35","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":696685,"visible":true,"origin":"","legend":"\u003cp\u003eTemporal evolution of oil saturation distribution under different injection schemes: (a–c) after 1 year, (d–f) after 3 years, and (g–i) after 5 years. Injection methods: water injection (a, d, g), CO₂injection (b, e, h), and CO₂–water co-injection (c, f, i).\u003c/p\u003e","description":"","filename":"Fig8.png","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1/fa92217a6dfe45a5db2a9b86.png"},{"id":88598873,"identity":"de066adc-8438-45e0-80bc-18018d4c12ac","added_by":"auto","created_at":"2025-08-08 07:31:35","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":608402,"visible":true,"origin":"","legend":"\u003cp\u003eTemporal evolution of water saturation distribution under different injection schemes: (a–c) after 1 year, (d–f) after 3 years, and (g–i) after 5 years. Injection methods: water injection (a, d, g), CO₂injection (b, e, h), and CO₂–water co-injection (c, f, i).\u003c/p\u003e","description":"","filename":"Fig9.png","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1/3ffadfb42e006c6baefa1493.png"},{"id":88598826,"identity":"aabf4359-ef00-46f6-94d7-05a6978d6ade","added_by":"auto","created_at":"2025-08-08 07:31:30","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":49803,"visible":true,"origin":"","legend":"\u003cp\u003eMass flow rate and \u0026nbsp;\u0026nbsp;cumulative oil production under different injection strategies: (a, b) water \u0026nbsp;\u0026nbsp;injection, (c, d) CO₂ injection, and (e, f) CO₂–water co-injection. \u0026nbsp;\u0026nbsp;Subfigures show injection mass flow rates (a, c, e) and cumulative oil \u0026nbsp;\u0026nbsp;production (b, d, f).\u003c/p\u003e","description":"","filename":"Fig10.png","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1/bd0e723c526e9ccb1fb88f4c.png"},{"id":108804513,"identity":"adf78dcf-0089-47e8-bd35-2937c9e5655f","added_by":"auto","created_at":"2026-05-08 15:21:06","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":861765,"visible":true,"origin":"","legend":"","description":"","filename":"1.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1_covered_26ecb463-e55b-4213-b7e9-21f73ae9af2f.pdf"},{"id":88598827,"identity":"a8d5a2c6-fed6-44e5-b1b9-7bac514316a6","added_by":"auto","created_at":"2025-08-08 07:31:30","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":154264,"visible":true,"origin":"","legend":"","description":"","filename":"Tables.docx","url":"https://assets-eu.researchsquare.com/files/rs-7185551/v1/dbb51bedb3b0c312c4a117c8.docx"}],"financialInterests":"\u003cp\u003eNo competing interests reported.\u003c/p\u003e\n\u003cp\u003eTables 1 to 3 are available in the Supplementary Files section.\u003c/p\u003e","formattedTitle":"Numerical Evaluation of CO₂, Water, and Combined CO₂–Water Injection for Enhanced Oil Recovery and Carbon Storage in Shale Reservoirs","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Shale oil reservoir, CO₂-EOR, Numerical simulation, Water–CO₂ co-injection, Oil recovery efficiency, CCUS","lastPublishedDoi":"10.21203/rs.3.rs-7185551/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7185551/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eUnder the global carbon neutrality goal, achieving synergistic benefits between enhanced oil recovery and geological CO₂ sequestration in shale reservoirs is of great significance. In this study, we constructed a numerical simulation model based on the geological settings of the Jiyang Depression in the Shengli Oilfield to investigate the performance of three injection strategies: water injection, CO₂ injection, and combined CO₂\u0026ndash;water injection. The simulations evaluated the evolution of reservoir pressure, oil saturation, CO₂ saturation, and water saturation over time. Results show that CO₂ injection offers the highest oil recovery and carbon storage potential, while co-injection exhibits a balance between injection stability and displacement efficiency. Compared with previous studies, this work provides a systematic and comparative analysis of multi-scheme injection performance, offering new insights into the optimization of EOR strategies and carbon storage in shale formations. 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