Optimizing Oil Recovery With Minimal Environmental Impact: Importance in Nigeria’s Brownfields

The Nigerian Oil and Gas industry is faced with a dual faceted challenge: a need to increase oil production in depleting mature brownfields and as well ensuring environmental sustainability during its exploitation processes. With brownfields, comprising 60-70% of the nation's remaining proven reserves, these assets exhibit significant volumes of bypassed, unrecovered hydrocarbons due to high reservoir compartmentalization and declining pressures. This paper explores the intersection of production engineering and environmental management to develop a strategic framework for sustainable Enhanced Oil Recovery (EOR). A comprehensive evaluation of EOR techniques reveals that while conventional thermal recovery is physically unsuited for the light sweet crudes of the Agbada Formation, advanced miscible gas injection (such as CO₂-WAG), with integration of Carbon Capture, Utilization, and Storage (CCUS) and green chemical flooding offer substantial promise. Furthermore, the study highlights the transformative role of digital optimization technologies in facilitating real-time decision-making and performance forecasting. Despite favorable laboratory and simulation outcomes, full-scale implementation remains bottlenecked by acute technical, economic, and regulatory barriers. To overcome these constraints, this paper proposes an integrated screening framework tailored to the Niger Delta, alongside recommendations for brownfield readiness assessments, targeted tax credits, streamlined inter-agency approvals, and robust local capacity development. Ultimately, this research provides the Nigerian Upstream Petroleum Regulatory Commission (NUPRC) and local operators with evidence-based benchmarks to operationalize sustainable asset management, bridging the gap between national energy security and environmental stewardship.

Niger Delta Brownfields, Enhanced Oil Recovery (EOR)

1. Adeyemi, O., Bello, K., & Okonkwo, C. (2022). Chemical EOR in Niger Delta reservoirs: Pilot performance and scalability constraints. Journal of Petroleum Science and Engineering, 214, 110482. [Google Scholar] [Crossref]

2. Adeniyi, A. O., & Utome, E. (2023). Carbon Capture, Utilisation, and Storage (CCUS) Integrated EOR: A Pathway to Net-Zero in the Nigerian Oil Industry. African Journal of Environmental Science and Technology, 17(4), 118–131. [Google Scholar] [Crossref]

3. Agi, A., Junin, R., & Gbadamosi, A. (2020). Chemical Enhanced Oil Recovery in High-Temperature, High-Salinity Reservoirs: Challenges and Green Alternatives for Mature Basins. Petroleum Science, 17(5), 1261–1279. [Google Scholar] [Crossref]

4. Agbasi, O. E., Esomchi, N. U., Daniel, A. E., & Udoka, J. U. (2023). Exploring reservoir potential of the X Field offshore Niger Delta Basin: An emphasis on lithofacies, depositional environments, and petrophysical characteristics. Jurnal Penelitian Fisika dan Aplikasinya, 13(1), 38–50. doi.org [Google Scholar] [Crossref]

5. Akpabio, J. U., Etim, R. N., & Nwuche, C. O. (2021). Enhanced oil recovery in Nigerian fields: Status, prospects and policy implications. Nigerian Journal of Technology, 40(1), 112–121. [Google Scholar] [Crossref]

6. Al-Ghamdi, A., Al-Hajri, N., & Al-Shehri, D. (2022). Alkaline-surfactant-polymer flooding in high salinity reservoirs: A review. Energy Reports, 8, 4567–4582. doi.org [Google Scholar] [Crossref]

7. Al-Jaber, M. S., Al-Murayri, M. T., & Al-Shuaili, K. (2025). Green ASP formulations for enhanced oil recovery in carbonate and sandstone reservoirs. Journal of Petroleum Science and Engineering, 245, Article 213456. [Google Scholar] [Crossref]

8. Amodu, A. O., Olayiwola, M. A., Omoboriowo, A. O., & Ojo, J. S. (2025). Geological and biostratigraphical factors in hydrocarbon recovery optimization using integrated seismic, petrophysical, and core data, Niger Delta. Open Exploration and Research of Energy Resources, 18, 100069. doi.org [Google Scholar] [Crossref]

9. Dioha, M. O. (2022). Nigeria’s energy transition plan: Opportunities and challenges for the oil and gas sector. Energy Policy, 171, Article 113289. [Google Scholar] [Crossref]

10. Djossou, F. K.-C. (2021). Feasibility analysis of ethane and flue gas injection for enhanced oil recovery with a Niger Delta case study [Master's thesis, African University of Science and Technology]. [Google Scholar] [Crossref]

11. DOE. (2021). Chapter Eight – CO2 Enhanced Oil Recovery. U.S Department of Energy. [Google Scholar] [Crossref]

12. Doust, H., & Omatsola, E. (1990). Niger Delta. In J. D. Edwards & P. A. Santogrossi (Eds.), Divergent/Passive Margin Basins (pp. 201–238). American Association of Petroleum Geologists Memoir 48. [Google Scholar] [Crossref]

13. Ekejiuba, A. U. (2018). Managing production decline in mature Niger Delta fields: A case study of waterflood optimisation. SPE Nigeria Annual International Conference and Exhibition, Lagos, Nigeria, August 6–8, 2018. SPE-193482-MS. doi.org [Google Scholar] [Crossref]

14. Ekong, S. U., George, N. J., Udoh, A. C., & Ekefre, A. E. (2025). Integrated reservoir characterization and bypassed hydrocarbon evaluation for optimized recovery in UDEN Field, Niger Delta, Nigeria. Researchers Journal of Science and Technology, 5(7). doi.org [Google Scholar] [Crossref]

15. Ekpotu, W., Udo, J., & Eke, V. (2024). Carbon capture utilization and storage potential in the Niger Delta: A pathway to net-zero. SPE Journal, 29(3), 1456–1472. [Google Scholar] [Crossref]

16. El-Masry, J. F., Mahmoud, M., & Kamal, M. S. (2025). Advances in green materials for chemical enhanced oil recovery. Fuel, 380, Article 133245. [Google Scholar] [Crossref]

17. Federal Ministry of Environment, Nigeria. (2021). Nigeria’s updated Nationally Determined Contribution to the UNFCCC. unfccc.int [Google Scholar] [Crossref]

18. Federal Ministry of Petroleum Resources. (2021). The Decade of Gas: Policy framework and implementation strategy. Government of Nigeria. [Google Scholar] [Crossref]

19. Federal Republic of Nigeria. (2021). Petroleum Industry Act, 2021 (Act No. 6 of 2021). Federal Government Printer. [Google Scholar] [Crossref]

20. Federal Republic of Nigeria. (2022). Nigeria’s energy transition plan. Federal Ministry of Environment. [Google Scholar] [Crossref]

21. Gbadamosi, A., et al. (2022). Application of Polymers for Chemical Enhanced Oil Recovery: A Review. Polymers, 14(7), 1433. pmc.ncbi.nlm.nih.gov [Google Scholar] [Crossref]

22. Gbadamosi, A. O., Junin, R., Manan, M. A., Agi, A., & Yusuff, A. S. (2019). An overview of chemical enhanced oil recovery: Recent advances and prospects. International Nano Letters, 9, 171–202. doi.org [Google Scholar] [Crossref]

23. Gbadamosi, A. O., Junin, R., Manan, M. A., Agi, A., & Yusuff, A. S. (2019). Recent advances and prospects in polymeric and surfactant-based chemical enhanced oil recovery—A review. Journal of Petroleum Exploration and Production Technology, 9(4), 2615–2632. [Google Scholar] [Crossref]

24. Ghorbanpour, H., et al. (2025). Comprehensive review of hybrid chemical enhanced oil recovery. Journal of Petroleum Exploration and Production Technology. doi.org [Google Scholar] [Crossref]

25. Green, D. W., & Willhite, G. P. (2018). Enhanced Oil Recovery (Second Edition). Society of Petroleum Engineers. [Google Scholar] [Crossref]

26. Hosseinifard, M., Ahmadi, M., & Mahdaviara, M. (2025). Hybrid nanofluid EOR techniques for brownfield applications. Journal of Molecular Liquids, 412, Article 126789. [Google Scholar] [Crossref]

27. IEA. (2019). Can CO₂-EOR really provide carbon-negative oil? IEA Analysis. iea.org [Google Scholar] [Crossref]

28. IFC. (2025). Nigerian CO₂ storage atlas. International Finance Corporation. [Google Scholar] [Crossref]

29. Idudje, H. E., Nwachukwu, A. N., Duru, U. I., Onyejekwe, M. I., & Onwukwe, S. I. (2025). Application of electrokinetics-assisted flooding for enhanced oil recovery in Niger Delta. Improved Oil and Gas Recovery, 9. [Google Scholar] [Crossref]

30. Jolley, S. J., Fisher, Q. J., Ainsworth, R. B., Vrolijk, P., & Delisle, S. (Eds.). (2010). Reservoir compartmentalization. Geological Society of London Special Publication 347. (background source underpinning the Niger Delta compartmentalisation literature) [Google Scholar] [Crossref]

31. Kadalfa, A. A. (2012). Environmental Impacts of Oil Exploration and Production in the Niger Delta of Nigeria. Global Journal of Science Frontier Research, 12(3), 19–28. [Google Scholar] [Crossref]

32. Kamal, M. S. (2025). Green materials used in enhanced oil recovery. Springer. [Google Scholar] [Crossref]

33. Kamal, R. S., et al. (2025). Green Materials Used in Enhanced Oil Recovery. IntechOpen. intechopen.com [Google Scholar] [Crossref]

34. Kerunwa, A., Izuwa, N. C., Dike, C. F., Okereke, N. U., Udeagbara, S. G., Obibuike, J. U., & Emenike, B. U. K. (2024). Review on the utilization of local ASP in the Niger Delta for enhanced oil recovery. [Google Scholar] [Crossref]

35. Lake, L. W. (1989). Enhanced oil recovery. Prentice Hall. [Google Scholar] [Crossref]

36. Lake, L. W., Johns, R., Rossen, W., & Pope, G. A. (2014). Fundamentals of Enhanced Oil Recovery. Society of Petroleum Engineers. [Google Scholar] [Crossref]

37. Lal, K. (2021). Artificial intelligence applications in enhanced oil recovery: A review. SPE Reservoir Evaluation & Engineering, 24(4), 789–805. [Google Scholar] [Crossref]

38. Maleki, M., Mahdaviara, M., & Riazi, M. (2025). Environmental assessment of hybrid EOR methods in mature fields. Environmental Earth Sciences, 84(7), 215. [Google Scholar] [Crossref]

39. Mbusube, M. M. (2024). Influence of reservoir heterogeneity on the implementation of polymer enhanced oil recovery (EOR) in the Niger Delta reservoirs [Doctoral dissertation, Heriot-Watt University]. [Google Scholar] [Crossref]

40. Mepaiyeda, B., Orodu, O. D., & Efeovbokhan, V. E. (2025). Machine learning approaches for EOR performance prediction in heterogeneous reservoirs. ChemEngineering, 9(1), 45. [Google Scholar] [Crossref]

41. NCDMB (Nigerian Content Development and Monitoring Board). (2022). Annual Nigerian oil and gas local content report 2022. Nigerian Content Development and Monitoring Board. [Google Scholar] [Crossref]

42. Nigerian National Petroleum Corporation. (2020). 2019 Annual Statistical Bulletin. NNPC. [Google Scholar] [Crossref]

43. Nigerian Upstream Petroleum Regulatory Commission. (2022). 2021 Oil and Gas Industry Annual Report. NUPRC. [Google Scholar] [Crossref]

44. NUPRC (Nigerian Upstream Petroleum Regulatory Commission). (2023). Brownfield development and EOR technical guidelines. Nigerian Upstream Petroleum Regulatory Commission. [Google Scholar] [Crossref]

45. Nigerian Upstream Petroleum Regulatory Commission (NUPRC). (2024). Environmental Guidelines and Standards for the Petroleum Industry in Nigeria (EGASPIN). NUPRC Regulatory Frameworks. [Google Scholar] [Crossref]

46. Núñez-López, V., Gil-Esteban, L., & Hosseini, S. A. (2019). Environmental and economic assessment of CO₂-EOR with CCUS in mature oil fields. Energies, 12(21), 4045. [Google Scholar] [Crossref]

47. Obiechina, G., & Ihejirika, D. (2021). Social licence to operate and oil production continuity in the Niger Delta: Implications for EOR investments. Energy Research & Social Science, 72, 101889. [Google Scholar] [Crossref]

48. Ogunbiyi, A. T., Ajayi, T. A., & Adeyemi, G. O. (2018). Produced water management in the Niger Delta: A review of challenges and opportunities. Journal of Petroleum and Environmental Biotechnology, 9(3), 372. doi.org [Google Scholar] [Crossref]

49. Oky, P. Druetta, et al. (2019). Chemical Enhanced Oil Recovery and the Role of Chemical Product Design, 113480. [Google Scholar] [Crossref]

50. Okafor, P., Amaechi, C., & Udoh, M. (2023). EOR economics in Nigerian brownfields: A Monte Carlo analysis of gas injection viability under PIA fiscal terms. Energy Economics, 118, 106509. [Google Scholar] [Crossref]

51. Olalekan, O., & Olafuyi, O. (2021). Technical Screening and Selection Criteria of EOR Methods for Niger Delta Oil Reservoirs. Journal of Petroleum and Coal, 63(2), 341–352. [Google Scholar] [Crossref]

52. Omotayo-Johnson, O., Ajaegwu, N. E., & Ogbe, O. B. (2023). Sedimentological and tectono-stratigraphic characterisation of a shallow-marine reservoir, 'Dona' field, offshore Niger Delta. Marine and Petroleum Geology, 157, Article 106487. doi.org [Google Scholar] [Crossref]

53. Onyemachi, J. C., Onwukwe, S. I., Duru, U. I., Chikwe, A. O., & Uwaezuoke, N. (2020). Enhancing oil recovery through nanofluids flooding with Irvingia gabonensis in the Niger Delta. Journal of Petroleum Exploration and Production Technology, 10(7), 2885–2894. doi.org [Google Scholar] [Crossref]

54. Oyeneyin, B. (2015). Integrated Sand Management for Effective Hydrocarbon Flow Assurance. Springer. [Google Scholar] [Crossref]

55. PwC Nigeria. (2021). Revitalising Nigeria’s brownfields: The next frontier for oil and gas growth. pwc.com [Google Scholar] [Crossref]

56. Purwasena, I. A., Astuti, D. I., & Fauziyyah, F. (2024). Biosurfactant production from agricultural waste for EOR applications. Scientific Reports, 14, Article 12345. [Google Scholar] [Crossref]

57. Saaty, T. L. (1980). The analytic hierarchy process: Planning, priority setting, resource allocation. McGraw-Hill. [Google Scholar] [Crossref]

58. Sanusi, O. M. (2017). Techno-economic feasibility of ethane-based enhanced oil recovery in Nigeria: Case study of the Niger Delta [Master's thesis, African University of Science and Technology]. [Google Scholar] [Crossref]

59. Sarafzadeh, P., Sarvi, M. N., & Rastegari, H. (2026). Biosurfactants for sustainable chemical EOR: Recent developments and future outlook. Scientific Reports, 16(2), 5678. [Google Scholar] [Crossref]

60. Shaikhah, D. M., Al-Hashim, H., & Al-Yousef, Z. (2024). Application of biosurfactants in enhanced oil recovery: A review. Journal of Petroleum Science and Engineering, 233, Article 212345. [Google Scholar] [Crossref]

61. Sheng, J. J. (2011). Modern Chemical Enhanced Oil Recovery: Theory and Practice. Gulf Professional Publishing. [Google Scholar] [Crossref]

62. Sheng, J. J. (2021). Enhanced Oil Recovery Field Case Studies. Gulf Professional Publishing. [Google Scholar] [Crossref]

63. Ugbedeojo, A., Appah, D., & Okoro, E. (2016). Production enhancement of a brown field in the Niger Delta using well intervention techniques. International Journal of Engineering Research & Technology (IJERT). [Google Scholar] [Crossref]

64. Umar, B. A., Olayinka, A. I., & Lawal, T. (2020). CO₂ storage potential in depleted oil and gas reservoirs in Nigeria. Journal of Natural Gas Science and Engineering, 84, Article 103612. [Google Scholar] [Crossref]

65. United Nations. (2015). Transforming our world: The 2030 agenda for sustainable development (A/RES/70/1). sdgs.un.org [Google Scholar] [Crossref]

66. United Nations Environment Programme. (2011). Environmental assessment of Ogoniland. UNEP. unep.org [Google Scholar] [Crossref]

67. Zhuang, Y., Li, J., & Wang, Z. (2025). Physics-informed neural networks for CO₂-EOR optimization. Computers & Geosciences, 187, Article 105789. [Google Scholar] [Crossref]

• An Adaptive Joint Filtering Approach to Wireless Relay Network for Transmission Rate Maximization
• IoT-Integrated Mercury Substance Detection System for Cosmetic Product Safety
• Design and Implementation of Solar PV-Based Railway Microgrid for Linke Hofmann Busch Coaches
• Cost Control Techniques on Civil Engineering Projects in Oyo State, Nigeria
• Strength and Predictive Modeling of Corn Cob Ash Blended Concrete Using Multi-Output Artificial Neural Network Approach