ANALYSIS OF OVERPRESSURE CHARACTERISTICS IN YANI SUB-BASIN, SUNDA BASIN

• Main Author: Lutfi Firdaus, Muhammad
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/73095
• Institution: Institut Teknologi Bandung

The Yani Sub-Basin is located north of the Sunda Basin and approximately 140 km north off the north coast of western Java. This sub-basin is one of the Tertiary age basins of the Sunda Basin. Pore pressure analysis is carried out to avoid drilling risks due to overpressure, such as kick, blowout, and loss. This research aims to estimate the pore pressure value using wireline log data, determine the depth of overpressure peaks, determine the mechanism that causes overpressure formation, and analyze the relationship between geological conditions and the presence of overpressure zones in the study area. This research was conducted on three wells in the Yani Sub-Basin using wireline logs, drilling reports, measured pressure data, temperature data, and source rock maturity data. The condition of the study area is used as a reference in estimating the pore pressure. The pore pressure estimation method used is the equivalent depth method. Based on the analysis results, the pore pressure in the study area consists of two conditions, hydrostatic and overpressure, with a loading mechanism. Peak overpressure starts from 6500-7000 ft depth. The overpressure zone is in the Talangakar Formation, caused by the rock's compaction failure, as evidenced by the wireline log analysis. The pore pressure in the overpressure zone ranges from 3000-6970 psi.