Tilted hydrocarbon water contacts, which are indicative of hydrodynamic traps, have been documented at several fields in the Kutai basin, Eastern Kalimantan, Indonesia (e.g. Badak, Semberah, Tambora, and Peciko). A hypothetical analysis is then performed to understand the possible driving mechanisms of the tilting and its future opportunity for new plays. Result of the hypothetical analysis shows that both gravity and compaction driven are responsible for the presence of the tilted hydrocarbon water contacts. Moreover, the analysis shows that hydrodynamic conditions may be present widely in this basin. Hypothetically, within the basin, the gravity driven hydrodynamics will cause groundwater flows from the western to the southern, northern, and eastern areas. Meanwhile, the compaction drive will cause groundwater flows from present time Mahakam Delta to western (onshore) and eastern (near offshore) areas. The compaction drive also present in the offshore sediments will cause groundwater flow in an onshore direction. As a consequence of the hydrodynamic condition within the basin, several new plays could be expected. Among the new plays are the nose of plunging anticlines and domal structures, and down-flow flank of an anticline. However, the downside of hydrodynamic flow conditions are that hydrocarbon flushing can occur, due to large hydraulic gradient such as in the nearby recharge area and basin depocenter. In order to ascertain the above hypothesis and also to get better understanding of Kutai Basin hydrodynamics, it is necessary that comprehensive hydrodynamics analysis be performed in this Basin. Numerical modeling of basin hydrodynamic has a capability to do such analysis.
Authors : Agus M. Ramdhan, Lambok M. Hutasoit & Richard E. Swarbrick