GCBD Implementation: Strike a Balance Between Dynamic in Gas Supply and Demand and Late Life Field Investment

The gas portfolio strategy in an oil field becomes significant as reservoirs or fault blocks approach depletion. An assessment of gas supply and demand reveals a potential shortfall in Peninsular and East Malaysia before 2026. This situation creates an opportunity to capitalize on associated gas and non-associated gas (NAG) to fulfill the demand, leveraging existing facilities that remain within their operational life. This will also enhance field recovery in late life and depleting fields before decommissioning. Gas Cap Blowdown (GCBD) involves a process of depressurizing the gas cap of an oil reservoir to produce the associated gas cap (AG) volumes, more often after the oil rim has been depleted of significant oil production. Notably, in Northeast Malaysia, the gas cap project has yet to be undertaken, as the predominant attention of future resource growth focuses on deepwater development. This underscores the strategic importance of optimizing gas resources and exploring new initiatives to address evolving energy demands in the region. Gas portfolio development and master plan is currently a high priority effort by host government since several oil fields, reservoirs or fault blocks are nearing depletion. Therefore, it is imperative to have a standardized approach for developing the Gas Cap reservoirs. This paper presents an insightful strategy for late field life management, focusing on key triggers for GCBD and how the project team secure appropriate approvals from the host government regulatory body for the development of gas cap resources in response to gas demand. From the lenses of host government, several key considerations or triggers should be in the primary evaluation in deciding optimum timing for partial or full blowdown as shown in Figure 1. Where gas development may impact existing or potential future oil development, key decision/triggers points are embedded in the workflow whether to further study, appraise, or accept that there is no scope for further oil developments and GCBD can be executed. Among the criteria are oil depletion, molecule tradeoffs, facilities age and its design limit, economic life and ultimately demand availability. Detailed study is required to determine the oil vs gas trade off evaluation on the timing of blowdown opportunities.