{"paper_id":"2eaebe6a-ea59-4556-a4aa-903ce6113d3f","body_text":"Gas Lift Network Optimization using Sequential Quadratic Programming in Mature Niger Delta Oilfield | 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 Gas Lift Network Optimization using Sequential Quadratic Programming in Mature Niger Delta Oilfield Isaac Eze Ihua-Maduenyi, Sunday Igbani, Eniye Oguta This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8403531/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Mature fields with declining reservoir pressure require artificial lift interventions to sustain production. This study evaluates gas lift optimization using the GAP network modeling platform integrated with Sequential Quadratic Programming (SQP) to maximize field oil output. Four wells were analyzed under separate and shared flowline configurations, considering multiphase flow, well inflow performance, and surface network hydraulics. Optimization scenarios dynamically allocated lift gas based on each well’s marginal oil-per-unit-gas response, while fixed-rate cases served as benchmarks. Results indicate that SQP-based optimization increases total field oil production by up to 5.8% under gas-limited conditions (5 MMscfd total lift gas) and maintains a 1–3% gain at higher gas availability (10 MMscfd). Optimized allocation reduced overall gas consumption for the same production levels, achieving savings of up to 15% in cumulative injection compared to uniform allocation. The separate flowline network consistently outperformed the shared configuration, yielding lower wellhead backpressure, improved drawdown, and higher oil rates, with differences up to 2.3% at mid-range gas volumes. Sensitivity analysis further highlights the impact of surface network parameters: increasing manifold diameter enhances flow efficiency, while elevated separator pressures and excessive manifold lengths introduce backpressure losses that reduce production. The study demonstrates that integrated SQP-based gas-lift optimization enables targeted gas distribution, maximizes field-level oil recovery, improves artificial lift efficiency, and informs operational decisions regarding network design and gas injection strategies. These findings provide a scalable methodology for optimizing gas lift in low-pressure, multiphase production systems. Gas lift optimization Sequential Quadratic Programming field production efficiency multiphase flow network hydraulics artificial lift reservoir deliverability Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers invited by journal 12 Jan, 2026 Editor assigned by journal 22 Dec, 2025 Submission checks completed at journal 22 Dec, 2025 First submitted to journal 19 Dec, 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. 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Journals\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":false},\"keywords\":\"Gas lift optimization, Sequential Quadratic Programming, field production efficiency, multiphase flow, network hydraulics, artificial lift, reservoir deliverability\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-8403531/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-8403531/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003eMature fields with declining reservoir pressure require artificial lift interventions to sustain production. This study evaluates gas lift optimization using the GAP network modeling platform integrated with Sequential Quadratic Programming (SQP) to maximize field oil output. Four wells were analyzed under separate and shared flowline configurations, considering multiphase flow, well inflow performance, and surface network hydraulics. Optimization scenarios dynamically allocated lift gas based on each well\\u0026rsquo;s marginal oil-per-unit-gas response, while fixed-rate cases served as benchmarks. Results indicate that SQP-based optimization increases total field oil production by up to 5.8% under gas-limited conditions (5 MMscfd total lift gas) and maintains a 1\\u0026ndash;3% gain at higher gas availability (10 MMscfd). Optimized allocation reduced overall gas consumption for the same production levels, achieving savings of up to 15% in cumulative injection compared to uniform allocation. The separate flowline network consistently outperformed the shared configuration, yielding lower wellhead backpressure, improved drawdown, and higher oil rates, with differences up to 2.3% at mid-range gas volumes. Sensitivity analysis further highlights the impact of surface network parameters: increasing manifold diameter enhances flow efficiency, while elevated separator pressures and excessive manifold lengths introduce backpressure losses that reduce production. The study demonstrates that integrated SQP-based gas-lift optimization enables targeted gas distribution, maximizes field-level oil recovery, improves artificial lift efficiency, and informs operational decisions regarding network design and gas injection strategies. 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