Abstract
A marginal field, projected for a 5-year production as part of a fast-track Field Development Plan (FDP), was established utilizing two wells. The wells were designed without gas lift capabilities, based on the anticipation of increased gas production. However, the actual gas-oil-ratio (GOR) diverged from the projected simulations, resulting in lower gas output. This discrepancy, coupled with decreasing reservoir pressure and increasing watercut, has led to challenges in sustaining the wells' production. To address these challenges, the implementation of In-Situ Gas Lift (IGL) application has emerged as a strategic solution to restore production.
The wells were completed with access to the gas zone and L reservoir, with side pocket mandrel positioned near the gas zone. To activate the gas zone, the operator performed well modelling to determine the optimal gas requirement, factoring in additional gas rate for Greenhouse Gas (GHG) management. The well models were updated to accurately reflect the latest well performance, with sensitivity analyses performed to explore optimization options. Integrated Network Modeling (INM) was also utilized, playing a crucial role in identifying strategies to enhance overall field performance and maximize both individual well productivity and network-wide efficiency.
The operator successfully revived two wells, achieving production rate of 2,100 bopd and securing 3.5 MMstb in reserves through IGL. Each well is anticipated to benefit from 0.3 – 0.4 MMScf/d in of IGL from the gas reservoir. For future planning, based on an integrated well-by-well review workshop, the operator has identified additional opportunities behind casing of multiple gas zones to provide lifting assistance. This is especially crucial for future wells planned for field development, which will also rely on IGL. IGL emerges as a cost-effective, robust solution for improving oil recovery in marginal fields, leveraging reservoir gas to ensure production stability. Its flexibility and low operational costs make it an ideal solution for optimizing production efficiency and extending the lifespan of assets in challenging operational environments.
This paper delves into the unique challenges faced and strategic approaches taken to extend the productive life of the field using IGL. It highlights the need for adaptability and innovation required in field development, especially when there are significant discrepancies between initial projections and actual production performance. The insights gained from this study offer valuable lessons for managing similar fields, emphasizing the critical role of continuous monitoring and flexibility in adjusting strategies within dynamic production environments.
