Production Optimization in Bonga Deepwater Through Rigless Intervention

Abstract Maximizing oil recovery and production remains paramount in Deepwater operations. This paper focuses on enhanced oil recovery and production optimization in the Bonga Deepwater project. Amidst the enduring challenges of sustained low oil prices in 2015, the team developed an optimized rigless intervention technology to manage the escalating cost associated with conventional rig base well intervention operations. Unlike traditional well interventions that often rely on expensive drilling rigs, the rigless approach provides a streamlined and economically viable alternative. In the first quarter of 2017, the Shell Nigeria Exploration and Production Company (SNEPCo) Deepwater team undertook a groundbreaking rigless well intervention initiative in Deepwater operations. The objective was to optimize well intervention procedures and reduce operational expenditures by introducing a cost-effective rigless technological approach for Deepwater well intervention in the Bonga field. This innovative technique effectively executed tasks like electric line, slickline, and acid bullhead stimulation operations. These operations aimed to bolster production rates and curb intervention expenses while maintaining stringent process safety. The outcome of the various well intervention campaigns was a game changer, as evidenced by the successful execution of twenty-two wells with diverse complexities and well intervention issues. These operations led to production enhancement and restoration, all achieved without process safety incidents or accidents. The implementation and subsequent adoption of this groundbreaking technology also set new records in the Deepwater environment. Notably, the deployment of the rigless technology at a water depth greater than 3281 ft emerged as an unprecedented and untested task. The technology also gave rise to other new sets of challenges. Establishing the reliability of the rigless intervention approach within the framework of the Bonga Deepwater operations posed a significant hurdle. Through detailed front-end planning, the challenges were effectively surmounted, underscoring the feasibility and potential of the rigless intervention strategy in overcoming complex well intervention operation scenarios. This paper presents details of the successful application of the Subsea Intervention Lubricator (SIL) package in conjunction with a Vessel of Opportunity for a rigless campaign. In response to the evolving operational demands and challenges, particularly those involving thru-tubing intervention, the study also showcases the development and effective use of an Integrated Riser-Based Vessel (Q7000). This novel approach addressed the limitations of conventional systems and provided valuable knowledge to asset owners seeking advanced techniques for offshore well intervention operations.