Publications

Fractured basement reservoir has become a future play in hydrocarbon exploration. However, several studies and concepts are still developing to date. As a part of Merang High of Jambi sub-basin, the study area is situated in a high structured basement, multi-phased tectonics, and composed of quartzite basement. By maximizing the use of recently acquired high resolution and beam migration 3D seismic data, this paper aims to evaluate the potential of fractured basement reservoir and find the sweet spots for the exploration target area. Various 3D seismic processing and analysis were generated to depict the distribution of the fractures which correlated with the actual geological condition. Subsurface mapping through seismic interpretation has also been conducted thoroughly as the structural framework becomes the main input for the modelling. Fractures were intensely found in certain areas through seismic attributes. Hence, the fracture modelling would comprehensively address that indication through demonstrating its intensity and orientation. The fractures modelling used Boundary Element Modelling (BEM) method, which utilizes fault interpretation, slip surfaces, and boundary conditions to assess strain values on each observation point. The method would predict type of mode, orientation and density of fractures. Two trends of NE-SW and E-W trending structures are well represented in the study area which complies with the two-phase tectonic history of the South Sumatera Basin. The present-day stress regime of strike-slip fault has SHmax azimuth of N67.5degE, which is generally obliqued with the average fracture orientation of N20-N30degE turned most of the fractures developed into critically stressed conditions. The areas with high critical stress value are considered to be reservoir sweet spots. Nevertheless, only drilling exploration would prove this basement potential sooner or later.