Sandstone facies distribution of potential reservoirs within lower talang akar formation in ‘Jasmine’ Field, Northwest Java Basin

Abstract

Abstract ‘Jasmine’ Field is an oil and gas field in the working area of a national oil company located in Northwest Java Basin. Lower Talang Akar Formation is considered to have one of the largest sandstone reservoir potentials in Northwest Java Basin based on earlier studies. This study aims to determine the depositional environment of Lower Talang Akar Formation and get the sandstone facies distribution of potential reservoirs in ‘Jasmine’ Field, as an early guideline for future production and drilling in new points within the field. Interpretation of this study was carried out by integrating 13 well log data, 13 well report data, 2 core data, and 1 3D seismic cube. Well log, well report, and core data were integrated to interpretate lithofacies, electrofacies, depositional environment, and stratigraphy sequence analysis. Sandstone body width vs. thickness ratio determination, fluid contact analysis, and RMS seismic attribute method were then carried to obtain the sandstone facies distribution of potential reservoir intervals of Talang Akar Formation in ‘Jasmine’ Field. The results shows that there are 2 intervals that has thick sandstone bodies as potential reservoirs in this study. The deposition direction for both Sandstone Body-A group and Sandstone Body-B group intervals is northeast-southwest. Sandstone Body-A group facies distribution is controlled by a braided river depositional environment and is distributed in the west side of the field. In the other hand, Sandstone Body-B group facies distribution is controlled by a distributary channel system in a lower delta-plain depositional environment and is distributed in both the west side and east side of the field.