ONE-DIMENSIONAL GEOMECHANICAL MODELING AND ITS IMPLICATION ON FAULT STABILITY IN 39A FIELD, SOUTH SUMATRA BASIN

• Main Author: Al Amin, Taufik
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/50310
• Institution: Institut Teknologi Bandung

Fault stability analysis was carried out in Falcon Structure, 39A Field, South Sumatra Basin. This analysis is conducted to determine the tendency of faults to experience reactivation which can be a risk in oil and gas production activities. In conducting this research, an analysis of the in-situ stress regime was carried out through one-dimensional geomechanical modeling. The study was conducted using the wireline log data, pressure test results, drilling reports, rock mechanics test results, and 3D seismic cube. Geomechanical modeling uses log data and pressure test results by applying the methods of Hubbert and Willis (1957), Mathews and Kelly (1967), Haimson and Fairhurst (1970), Zoback and Healy (1984), Barton et al. (1988), and Zoback et al. (1989). The modeling results can be applied in the stability analysis of faults which include slip tendency (Ts), dilation tendency (Td), and fracture stability (Fs). The results of geomechanical modeling show that the insitu stress regime in 39A Field is currently dominated by strike-slip fault regimes. Image log data shows the maximum horizontal stress direction is N60°E that corresponds to the direction of the far-field field stress due to the subduction of the Indo-Australian plate beneath Eurasian plate. Fault stability analysis shows that faults in 39A Field are more likely to experience dilation than slip. In addition, a pore pressure perturbation is needed with average maximum 41.6 MPa thus the faults could be reactivated.