Publications

The Bungamas PSC is located in the southwestern margin of the South Sumatra Basin, more specifically on the western edge of the South Palembang Sub-basin, an intervening graben initiated in Paleogene time. It was subjected to Mid-Miocene wrenching and subsidence. Plio-Pleistocene compression resulted in the formation of WNW-ESE trending folds. Since 2009, a total of 725 km of new 2D seismic data has been acquired, six exploratory wells were drilled with attendant laboratory analyses, and surface mapping was completed. This wealth of newly acquired data was combined with publicly available regional information to conduct a petroleum system analysis to fully understand the hydrocarbon potential of this block. Basin modeling started with a 1D burial history and hydrocarbon expulsion model of all wells. The results were translated to a 2D/3D model to consider hydrocarbon migration and accumulation. The petroleum system is active in this structurally inverted area. Hydrocarbons are believed to be generated predominantly from Talang Akar source rocks starting as early as Early Miocene. Dark shales of the Gumai Formation began expelling hydrocarbons as early as Middle Miocene. Following initial hydrocarbon migration in the area, secondary migration may have occurred due to the latest deformation. Very shallow hydrocarbon accumulations are common as tested by several shot holes during the latest seismic acquisition at 100 feet depth. Escaping hydrocarbons are expected as the Pliocene Muara Enim Formation is outcrops in many parts of the block. The thickness of the eroded section and the basement structural configuration turned out to be the critical parameters in this exercise. The missing section varies significantly within a short distance. Careful attention to these events has resulted in a more reliable basin model.