Publications

The Sepinggan Strike-Slip Fault System is widely known to control the structural configuration and hydrocarbon distribution in the Balikpapan Bay Area. The fault system extends more than 70 km trending SE-NW and is part of the greater Adang Fault Zone. This strike-slip fault system traverses several fields and plays a significant role in hydrocarbon accumulation in the Balikpapan Bay Area. More than 100 MMBOE hydrocarbons have been produced to date in this area from two group plays, Early Miocene Deltaic Play, and Middle Miocene – Pliocene Deltaic Play. Future exploration in this area is directed towards the more challenging plays with overpressure zone. This study looks at eleven fields in the Balikpapan Bay to understand the pore pressure distribution across the structurally complex area. Multi-vintage seismic, exploration and development wells are utilized for this purpose. This study has found that structural geology controls the pore pressure configuration in this area. The fault block movement seems to correlate to the top of overpressure. In the uplifted fault blocks, the top overpressure appears at the shallower depth even fully dissipated in highly eroded areas. Otherwise, in the lowered fault blocks, the top overpressure appears at the deeper depth. The top of overpressure in the Balikpapan Bay appears at different stratigraphic intervals across the observed fields. The top of overpressure varies from Early Miocene to Middle Miocene to the present day. The result of this study provides an insight into pore pressure configuration in structurally complex areas.