Horizontal Well Optimization With Inflow Control Devices (ICDs) Application in Heterogeneous and Dipping Gas-Capped Oil Reservoirs

Abstract

Abstract SS field is located offshore East Malaysia. 2 exploration wells discovered multiple dipping reservoirs, with oil column of about 40 m. The heterogeneous reservoirs, combined with a very large gas cap (i.e. m size of 2) and moderate aquifer strength impose challenges to maximize recovery from this field. Field development study has formulated 14 horizontal wells with 3 water injectors to achieve recovery factor of 30%. Optimum reservoir management strategy requires a delicate balance of gas cap expansion and water injection drive, where the optimum voidage replacement ratio is only 0.25. However, reservoir dynamic modelling shows that all the wells will get early gas and water breakthrough. ICD technology is therefore evaluated to address the above production and recovery dilemma while prolonging the production life. In this paper, optimization of 12 horizontal ICD wells out of 14 wells will be discussed. This includes the process of qualifying and designing the ICD application in each candidate through static modelling. Full field dynamic modelling was also conducted to quantify the real benefits of ICD, and confirming the robustness of the design throughout field life. In view of high uncertainty of fluid contacts and reservoir quality in unappraised areas, the team has adopted the unique yet challenging approach of field appraisal from pilot holes during the initial implementation stage. This has provided valuable data prior to horizontal drilling and final optimization of ICD. Subsequently, the production performance from the first ICD wells will also be discussed to provide evidence on its effectiveness and lessons learned. Finally, the paper highlights the importance of seamless teamwork and coordination between project team and service providers to deliver superior performance. This can be an informative workflow source for future applicants of such technology with similar fields’ nature and risks.