Perpustakaan Digital ITB

Indonesia continues to rely heavily on oil and natural gas as its primary energy sources, despite a downward production trend caused by aging wells and limited new discoveries. To meet increasing domestic energy demand, hydraulic fracturing has emerged as a key stimulation technique, especially in low-permeability reservoirs. However, the success of fracturing is often uncertain due to geological and geomechanical heterogeneity. This study aims to reduce that uncertainty by evaluating reservoir fracability using brittleness and fracability indices derived from petrophysical and geomechanical log data. A comprehensive methodology was developed, consisting of log interpretation, rock mechanical properties analysis, index calculation, and identification of fracable intervals. The analysis uses well log data from Well-X, located in West Java. Elastic parameters such as Young’s modulus and Poisson’s ratio were derived and calibrated to static conditions to better represent in-situ rock behavior. These were used to calculate the brittleness and fracability indices using a modified Rickman approach. To improve representativeness, local cut-off values were established through statistical analysis, with a brittleness index > 16.3559 and fracability index < 1.4298 found to best reflect the characteristics of soft sandstone formations. The analysis identified three potential zones (Formations P, Q, and R). These intervals are characterized by high brittleness, large Young’s modulus, low Poisson’s ratio, and low ?/? ratios, with formation Q as the primary the target for hydraulic fracturing due to its positive oil indications. This study demonstrates that integrating local petrophysical and geomechanical data improves the reliability of fracability evaluation, ultimately supporting more efficient and targeted stimulation design in similar soft sandstone reservoirs.