Study Investigates Feasibility of Conversion of Production Facility in Depleted Gas Field for CCS

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 221312, “Feasibility Study of Conversion of Old Production Facility in Depleted Gas Field to CCS Facility Through International Joint Research With the Netherlands: Case Study,” by Suho Cha, Sunghyun Park, and Jonghwan Kim, Hyundai, et al. The paper has not been peer reviewed. _ The objective of this study is to ascertain the capital expenditure (CAPEX) and operating expenditure (OPEX) associated with the reuse of existing facilities. To this end, a joint research initiative has been launched between Hyundai and the Netherlands, which is engaged in a comparable carbon capture and storage (CCS) project in the East Sea. The aim is to identify potential cost savings for the CCS project currently being prepared in South Korea. Introduction The concept of reusing aging production facilities in depleted gas fields for CO2 storage offers various advantages. These fields often come with existing offshore infrastructure, thereby reducing CAPEX required for CCS projects. In the case of the East Sea gasfield CCS project in South Korea, Hyundai, in collaboration with the Korea National Oil Corporation, conducted a prefront-end engineering and design study to evaluate the feasibility of converting the depleted gas field into a CO2 storage site. While reusing existing infrastructure in depleted gas fields offers cost advantages, the construction of new CO2 injection facilities in saline aquifers presents another viable option for large-scale CO2 storage. The development of new CO2 injection facilities in saline aquifers requires a comprehensive understanding of the geological characteristics of the storage site. One of the critical challenges in developing new CO2-injection facilities in saline aquifers is the lack of existing infrastructure, which results in higher CAPEX compared with repurposing old facilities. Methodology This study involves an economic analysis and case study of the following four scenarios: - Case 1—Economic evaluation of constructing a CO2 injection plant by reusing old facilities in a depleted gas field - Case 2—Economic evaluation of constructing all-new facilities for CO2 injection in a saline aquifer in the same area as the depleted gas field - Case 3—Economic evaluation of constructing all-new facilities and transporting CO2 by pipeline when the new platform is 100 km offshore - Case 4—Economic evaluation of constructing all-new facilities and transporting CO2 by ship when the new platform is 100 km offshore This study is conducted at the feasibility stage, and the economic evaluation is based on limited design and cost-estimation data at the block-flow-diagram level, corresponding to the Association for Advancement of Cost Estimating International preliminary Class 4 cost estimate. A Class 4 estimate is suitable for evaluating feasibility-study-design alternatives, aiming for an accuracy of approximately 30%. The investment-cost estimation in this project relies on cost-estimation models included in reliable public literature. The results of this Class 4 cost estimation provide sufficient value for the feasibility-study stage and will be refined to an accuracy range from ±5 to ±10% through the phases detailed in the paper as the project progresses.