Wellwork on a Deepwater Producing Asset, Transformed

Abstract

This paper presents a comprehensive transformation in productivity impacting intervention strategies for a mature deepwater subsea field. As the field entered its decline phase, traditional well interventions became harder to economically justify. The target field adopted a holistic well intervention cost reduction and a production uplift assurance strategy that encompassed the entire operational chain: reservoir, wells, plant, and export. The authors detail the mindset shift and the innovative approaches that fundamentally changed the outcome of well interventions: Reservoir Management: A shift to proactive, root-cause-driven interventions, determining the actual causes of production decline (such as asphaltene and scale deposition) rather than deploy generic chemical treatments to treat all possible threats, resulting in cheaper and lower volume treatments.Well Execution: Introduction of new execution methods, including rigless manifold pumping and high-rate production riser stimulations, which leveraged the unique subsea infrastructure to reduce non-productive and execution time, costs, and enable multi-well campaigns.Plant and Export Optimization: Streamlining flowback operations and minimizing the need for export system involvement, which further reduced costs, risk and operational disruptions. The most recent campaign, utilizing these strategies, achieved a safer, five-well intervention campaign 75% lower in cost than traditional means of execution. This not only cemented the economic viability of future interventions but also maximized resource recovery and ensured the long-term productivity of the field.