Application of 3D Fractures Modeling in Exploring Basement Fractured Reservoir Potential

Recently, naturally basement fractured reservoir is becoming one of the main exploration target for many basins in particular Western Indonesia. Exploration specifically for naturally fractured basement reservoirs has been known to encounter serious problems. Understanding fratures distribution particularlly in the basement is one of the most important components in evaluating new play in this petroleum basin. In addition, understanding fractures characteristics (type of fractured-reservoirs, fracture distribution, strorage capacity of the medium and interflow-porosity behavior) particularlly in the fractured-basement reservoir is very important besides to estimate the boundary of the reservoir. These can be done using integrated approach of detailed structural mapping using 2D/3D seismic, anomaly gravity and magnetic maps, fractures mapping using image log, palinspatic reconstructions using balancing cross-section and static modeling. The main purpose of this paper is demonstrated results of developing exploration concepts and workflow for basement fractured reservoir target using integrated approach in the Iliran High, South Sumatra Basin, Indonesia. The results of study indicate that Iliran High show moderate to high risk basement fractured reservoir potential. Fractures observed in the wells, their density is controlled by lithology types showing higher density in granites. 3D fractures modeling indicated that average basement fractured porosity is 1 -2%.