Journal of Geoscience and Eco Agricultural Studies

Abstract

This study assesses the CO₂ storage potential of an aging well in the South Sumatra Basin through the interpretation of conventional well log data, including gamma ray (GR), bulk density (RHOB), neutron porosity (NPHI), deep and shallow resistivity logs (LLD and MSFL), and caliper measurements. The evaluated interval, ranging from 1200 to 1800 meters, is subdivided into an upper formation (1200-1500 m) and a lower for mation (1500-1800 m). The upper formation exhibits low gamma ray values but minimal separation between porosity and resistivity logs, suggesting low porosity and permeability, characteristics indicative of a potential cap rock. In contrast, the lower formation reveals distinct separation in both porosity and resistivity responses below 1650 meters, indicative of a porous sandstone with favorable reservoir properties. Petrophysical analysis yields an average effective porosity of 14.4% and an irreducible water saturation of 6.4%. Volumetric calculations estimate a theoretical CO₂ storage capacity of approximately 1.21 million metric tons per square kilometer. These findings demonstrate the feasibility of repurposing aging wells for CO₂ sequestration and emphasize the utility of well log analysis in early-stage site screening, particularly in data limited sedimentary basins.