TRIGONOMETRIC APPROACH TO CURVED PSEUDO ELASTIC IMPEDANCE (CPEI) AND PSEUDO ELASTIC IMPEDANCE - LITHOLOGY (PEI-L) ATTRIBUTE FOR CARBONATE RESERVOIR CHARACTERIZATION IN THE KUJUNG FORMATION 'EVI' FIELD, EAST JAVA BASIN

• Main Author: Carreta Wibowo, Zefany
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/77963
• Institution: Institut Teknologi Bandung

The 'EVI' field is located in the East Java Basin, which is part of a back-arc basin, situated at the southeastern boundary of the Eurasian Plate. This basin contains several reservoir rocks, one of which is carbonate rock in the Kujung Formation, which is the focus of this research. Analysis of well log data indicates that AI (Acoustic Impedance) and vp/vs (P-wave to S-wave velocity ratio) are sensitive elastic parameters. Seismic inversion using linear programming sparse spike analysis was conducted with AI and extended elastic impedance for vp/vs. The inversion results tend to be biased for non-dominant AI and vp/vs values. Therefore, CPEI (Curved Pseudo Elastic Impedance) attributes, involving fluid trends, and PEI-L (Pseudo Elastic Impedance – Lithology) attributes, involving compaction trends, are used. The CPEI attribute shows a correlation of 0.80423 with water saturation, while PEI-L has a correlation of -0.76167 with porosity. Porosity and water saturation transformations are used to estimate volumes. The low values of AI, vp/vs, CPEI, PEI-L, and water saturation, along with high porosity, indicate that the 'EVI' field, from the lower part of the Top_Kujung to Kujung II, is likely a porous reef build-up filled with hydrocarbon fluids.