Perpustakaan Digital ITB

In order to reduce emissions and achieve net-zero emissions by 2050 due to the Paris Agreement’s goal in 2015 of constraining temperature rises to 1.5°C and Indonesia’s targets of a reduction of greenhouse gas emissions by 29% in 2030 and up to 41% with international support. One of the strategies that can be conducted is to perform CO2 storage in geological formations. One of the viable alternatives to geological storage is depleted gas reservoirs because of several advantages, including the fact that for numerous years, natural gas has been proven entrapped in that structure. Therefore, it is necessary to perform an analysis to estimate the storage capacity of the CO2 that can be utilized. The analysis starts with determining the Initial Gas in Place (IGIP) using the p/z method. The analysis carried out is by constructing a p/z versus Gp plot, then extrapolating a straight line to the Gp axis when p/z is 0. Based on the event of decreasing reservoir pressure as the production process. Observing pressure behavior in the reservoir is necessary to assess the possibility of ‘abnormally pressure’. If ‘abnormally pressure’ is detected occurs in the field, then the p/z plot should have two separate slopes for the extrapolated straight lines that show the ‘apparent’ Initial Gas in Place (Gapp) that leads to an overestimated value and the ‘actual’ Initial Gas in Place (G). The material balance equation by Tseng, Hsieh, Hu, & Lin and IPM-Mbal software were utilized in this study to determine CO2 storage capacity. In the injection process, it is targeted that the reservoir pressure will be reverted from the abandonment pressure and return to the initial reservoir pressure. The preshc/CO2/zreshc/CO2 versus Gphc-GinjCO2 plot for injection and production is generated. CO2 storage capacity is greater than natural gas production in total volume. Based on the analysis, the ‘abnormally pressure’ occurred in this field, and the ‘actual’ Initial Gas in Place (G) is 381.88 BSCF using the equation by Dake a 92.38% recovery factor. Also, for the IPM- Mbal software, it is 380.56 BSCF with a 92.71% recovery factor. The CO2 mass storage capacity (MinjCO2) results from the equation by Tseng, Hsieh, Hu, & Lin is 0.042 gigatonnes and the IPM-Mbal software is 0.039 gigatonnes.