Assessment of CO2 Storage in DF1-1 Gas Field South China Sea for a CCS Demonstration

Abstract

Summary DF1-1 gas field is located in the west of the South China Sea, which is associated with high concentration of CO2. Currently CO2 separated from the natural gas stream is emitted into the atmosphere. In this study, a demonstration project of CO2 capture and storage (CCS) is considered, proposing to inject CO2 separated on the platform back into the original gas reservoir. The CO2 storage site considered is a nearly abandoned gas block in the DF1-1 gas field, which was reassessed for the safety of CO2 storage. Membrane separation technique will be installed on the platform for the separation. CO2 is compressed at a super-critical state and injected through a single well (used to be a producer) into the gas formation. A new platform auxiliary to the main platform will be built to accommodate the compressor and separation equipment. CO2 will be injected at the rate of 0.14 million Sm ³ for 10 years over the field development period. At the end of the project, the pressure of the CO2 storage reservoir will be increased to its original pressure. Scoping economic analysis shows that the CO2 storage cost of the project is around US$20 per ton CO2, in which the auxiliary platform is the main cost factor.