Quantitative Lateral Seal Capacity for Carbon Capture Storage Evaluation: The Case from the Gulf of Thailand

Summary Sedimentary basins in the Gulf of Thailand initially opened in the Oligocene by continental rifting. Syn-rift lacustrine basin fill contains primary source rocks that charged hydrocarbons to the Miocene fluvio-deltaic post-rift reservoirs. Starting in the Pliocene, the depositional environment progressed to shallow marine, providing a shale-rich interval that acted as regional top seals. The petroleum system was completed by the peak hydrocarbon migration in the Pliocene. This study illustrates fault seal capacity in two perspectives: hydrocarbon exploration and production and CCS. It is observed that fluvio-deltaic depositional environment can contain considerable shale proportion providing a low threshold SGR (0.2) required for hydrocarbon trapping. The seal failure envelope can be used for initial estimation of CO2 storage volumes in CCS project evaluation. The pressure vs depth profile shows that fault seal capacity in the study area has a linear relationship with that of intact top seal strata, which can be useful in exploration and new development projects. This study demonstrates the application in CCS of hydrocarbon fault seal calibration based on well data.