Utilizing the Gravity Method for Initial Estimation of CO₂ Storage Capacity in Supat Field, South Sumatera

Abstract

Carbon Capture and Storage (CCS) technology is one of the solution to global warming. CCS is a method that involves separating CO2 from industrial and energy sources, transferring it to storage, and isolating it from the atmosphere for long periods of time. The Supat Field, South Sumatra is one of the mature oil and gas fields that could be used for CO2 storage in Indonesia. The gravity method is used to determine how much volume of CO2 can be stored in the Talang Akar Formation, Supat Field. By utilizing residual anomaly gravity data and the combination of Occam and Singular Value Decomposition (SVD) inversion method, it is possible to model in three-dimensions and estimate the volume of CO2 that can be stored in the field. The Talang Akar Formation is dominated by sandstone with interconnected porosity. The effective volume can then be calculated by multiplying the bulk volume by the range of sandstone porosity (15-30%), which can be known via gravity method. The Complete Bouguer Anomaly Map provides a range of Bouguer anomaly values between 42 mGal to 46 mGal. Based on the spectrum analysis graph, the anomaly depth limit is 2.0996 kilometers below the surface, while the residual anomaly depth limit is 0.9524 kilometers below the surface. The anomaly separation technique used is Polynomial Trend Surface Analysis with the order used is first order. The effective volume of CO2 that can be stored in the Supat Field ranges from 1.73 to 4.42 km 3.