Environmental and economic considerations for the decommissioning of oil and gas infrastructure in Nigeria.

Ayeni, M.; Iyalla, I.; Mahon, R.

Abstract

When offshore structures reach their end of life it becomes necessary to remove them and return the environment to its initial state. Generally, there are three options for decommissioning which are complete removal, leave in place, and partial removal. The choice of option takes into consideration, economic environmental, technical, safety, stakeholders, and regulatory factors. This work aims to critically evaluates the environmental, economic, and regulatory aspects of oil and gas facility decommissioning in Nigeria and assesses the feasibility of various strategies in minimizing environmental impact and decommissioning cost. Following best practices of the United Kingdom, a leading country that has decommissioned several offshore facilities, the study highlights the challenges and opportunities associated with the Nigeria environment. A systematic approach was employed to evaluate the strategies, utilizing both ranking systems and sensitivity analysis. The findings indicate that the choice of decommissioning strategy has multifaceted implications, necessitating a thorough evaluation process. The study also proposes establishing a "Decommissioning Fund" and offering tax incentives for decommissioning activities. Technological advancements such as modern bond logging techniques, rig less intervention equipment and innovative containment approaches is deemed crucial for cost reduction and enhancing efficiency of decommissioning process. Theoretical insights derived from this study offer a fresh perspective on decommissioning in the Oil and Gas sector, highlighting both its challenges and opportunities. Practical implications of the findings are also discussed, providing industry practitioners with actionable recommendations.

Citation

AYENI, M., IYALLA, I. and MAHON, R. 2024. Environmental and economic considerations for the decommissioning of oil and gas infrastructure in Nigeria. In Proceedings of the 2024 Society of Petroleum Engineers (SPE) Nigeria annual international conference and exhibition (NAICE 2024), 5-7 August 2024, Lagos, Nigeria. Hosted on OnePetro [online], paper number SPE-223134-MS. Available from: https://doi.org/10.2118/223134-MS

• Presentation Conference Type: Conference Paper (published)
• Conference Name: 2024 Society of Petroleum Engineers (SPE) Nigeria annual international conference and exhibition (NAICE 2024)
• Start Date: Aug 5, 2024
• End Date: Aug 7, 2024
• Acceptance Date: May 20, 2024
• Online Publication Date: Aug 5, 2024
• Publication Date: Aug 5, 2024
• Deposit Date: Sep 12, 2024
• Publicly Available Date: Oct 8, 2024
• Publisher: Society of Petroleum Engineers
• Peer Reviewed: Peer Reviewed
• Article Number: SPE-223134-MS
• ISBN: 9781959025474
• DOI: https://doi.org/10.2118/223134-MS
• Keywords: Air emission; Well decommissioning; Consideration; Social responsibility; Nigeria; Sustainability; Platform; Offshore facility decommissioning; Subsea system; Installation
• Public URL: https://rgu-repository.worktribe.com/output/2474889
• Additional Information: The files accompanying this record are the presentation slides. The full-text paper is available to purchase from OnePetro: https://doi.org/10.2118/223134-MS