Publications

South Sumatra Basin has been a prolific oil and gas producer since the Dutch era from Tertiary reservoirs. Nowadays exploration in this mature basin is getting deeper into Pre-Tertiary rocks where fractured basement is the main target. Where oil and gas exist in fractured basement reservoirs this might be held within an extensive fracture network on a variety of different scales rather than within the matrix porosity of the formation. This presents challenging subsurface evaluation for exploration geoscientists. The study was conducted in “Giant” Area, Jambi Sub-Basin, which contains granite and quartzite as basement rocks. Borehole resistivity, acoustic image and 3D seismic evaluation data sets are used to characterize fractured basement in “Giant” Area. The interpretation of resistivity and acoustic data resulted in a fracture dataset which includes dip, dip azimuth, and strike which will deliver vertical fracture orientation and its tectonic history. Discontinuities such as faults and fractures were distinguished using structural seismic attributes such as structural smoothing, variance, and supervised ant-tracking. Fracture set based on image analysis shows average of fracture dip 40°-60° with major strike orientation of NE-SW. Seismic attributes clearly show the discontinuities in major NW-SE and NE-SW orientation based on variance (0.7-1.0), aggressive ant-tracking (0.00-1.25), and RMS amplitude supervised ant-tracking (0.90ms – 0.92ms). Integrated analysis of image-based fracture development in the “Giant” Area is related to faulting. A 3D geological model was made statistically resulting in distance to fault, ant track resampling, and fault patches extraction to determine two proposed wells to prove basement fractured reservoir play concept in Jambi Sub-Basin.