Gas management in mature producing oil and gas fields within an integrated facility network poses numerous challenges due to complex facility interdependencies and constraints. A review of the short-term gas demand and supply projections within a key gas gathering hub highlights a significant gas supply shortage for injection, hindering realization of the full oil value potential through gas injection.
This paper presents the development of an integrated strategy to optimize the utilization of associated gas supply within existing facility constraints, aimed at maximizing overall value. A multidisciplinary approach, including holding workshops to review field performance, analyze gas injection requirements, and identify opportunities to manage supply gaps, was adopted. A framework was established to prioritize gas injection based on Additional Oil Recovery (AOR), departing from the conventional allocation method that prioritizes gas distribution solely based on the contributions of each field to the gas gathering hub. The approach ensures gas distribution is optimized to maximize incremental oil production derived from gas injection.
Proposed strategies to mitigate near-term supply short falls include prioritization, external gas sourcing, gas cap blowdown and utilization of high GOR wells. Collaborative efforts have resulted in improved near-term injection benefits despite limited gas supply, with recent reservoir pressure trends indicating reservoirs are positioned to deliver expected mid- and long-term value. The Reservoir Engineer played a pivotal role as a central interface and coordinator in achieving effective gas management.