Development of Marginal Hydrocarbon Resources with Innovative Completion Strategy

Abstract The development of marginal hydrocarbon resources, such as some small pockets of hydrocarbon in stacked reservoirs within the Ogbele field, presents significant technical and economic challenges due to low recovery and uneconomic outcomes associated with attempting to develop using conventional completions strategies that focus on producing either oil or gas from a well. This paper presents Aradel's approach to developing marginal hydrocarbon resources that would traditionally have remained undeveloped due to low recovery and ultimately not passing economic evaluation. Aradel Holdings have implemented a fit-for-purpose innovative completion strategy in its wells in the Ogbele field wells where single and/or dual-string completions are designed to produce both oil and gas streams from the same well. The approach has oil and gas fluid streams produced simultaneously with two strings in a well (gas in one an oil in the other), or sequential production of both oil and gas fluid streams from a single string (oil production first and later gas production – bottoms up approach). This paper presents this novel approach, highlighting potential risks as well as mitigation strategies that ensure minimum oilfield safety standards are not compromised. The lessons learnt provide a practical framework for creating value by unlocking the potential of similar marginal fields and reservoirs, significantly contributing to the country's developable hydrocarbon reserves, creating value from previously uneconomical marginal resources.