Enhancing CCS Well Design in Depleted Reservoirs

Abstract The decarbonization of the energy section urges a radical transformation to meet the net zero carbon emission target. In the last decades, many countries around the world have initiated the Carbon Capture and Storage (CCS) as one of the pilot projects aiming to permanent and environmentally safe storage of CO2 underground. However, only a few projects have strived and is eventually executed. Ones of the biggest challenges are technicality and commerciality to drive the success of the project. Thus, the objective of this paper is to mainly focus on the CCS well construction, design consideration, and optimization in Southeast Asia offshore CCS projects during the detailed planning phase. The process will start with the reservoir injection targets. Each well is planned to inject one single target to minimize the complexity of well architecture and completion equipment. Inevitably as being common in this area, stacked reservoirs or multi-target reservoirs are exceptional to achieve the intended CO2 injection target with a higher complexity level of completion equipment. Wellhead platform is a huge capital investment. Reuse of existing platform or new wellhead platform brings advantages and disadvantages. The key concerns include slot recovery issues, collision risk, fatigue concern on platform structure, and so on. The detailed consideration has been laid out to ensure the platform integrity and meets the expected design life. Well construction process is similar to normal oil and gas wells, but the main differences are CO2 injecting fluid and load cases analysis. Thus, material selection plays a major role for the well construction process to align with flow assurance study result and expected load case when majority of the worst-case scenario might occur in the late life injection. Material optimization is a key to bring the well construction cost down. Material testing has been constructed as per the expected downhole condition for the verification and optimization purposes. Detailed study of each type of wells are necessary to ensure the casing and completion equipment is fitted for purpose during the well life cycle. The Measurement, Monitoring and Verification (MMV) equipment is embedded since the designed phase with the ranking technique to comply with conformance and containment criteria.