petroleum potential of forearc basin
DESCRIPTION
The Bone Basin is situated between thesouthwestern volcanic arc and southeasterncollision complex of South Sulawesi region. Thebasin is clearly rimmed by major N-S orientedmarginal faults, sub parallel to its axis. Thesouthwestern margin of the basin is bounded byN-S oriented Walanae and West Bone Bay FaultSystems, while the northeastern margin of the basinis bordered by East Bone Fault System. Threemain depocentres can be identified in this area.Firstly, the easterly dipping depocentre, known asNorth Bone Sub-basin, is located in the northern tipof the basin. The other two depocentres are locatedin the southwestern part of the Basin. One is awesterly dipping half graben system of South BoneSub-basin, which is bounded in its western marginby the easterly dipping of West Bone Bay FaultSystem. The other depocentre is located in thesouthwestern most part of the basin and is typifiedby an easterly dipping half graben system of theSW Bone Sub-basin. It is bordered on its easternmargin by the westerly dipping Walanae FaultSystem.TRANSCRIPT
Petroleum potential of Forearc Basins
Author(s): Rudiger Lutz, Kai Berglar, Imke Struss, Stefan Schloemer, Bernhard Cramer,Jutta Winsemann, Christoph Gaedicke, Yusuf S Djajadihardja
Forearc basins develop as a result of plate subduction and are situatedoffshore between an outer arc high which in some cases emerges above sealevel (e.g. offshore Sumatra) and the main land. So far these regions are notconsidered as important petroleum provinces because low heat flow does notnecessarily support relevant petroleum generation. In addition, thedepositional environment of many forearc basins is dominated by a highclastic sediment supply from adjacent land masses with low content oforganic material.To revise these preconceptions, petroleum systems of forearc basins fromthe Middle American and Sunda Arc trenches were investigated in detail.The forearc basins of the Sunda Arc extend from northern Sumatra in thenorth to eastern Indonesia in the south. Multichannel seismic data have beencollected in a joint project of BGR and BPPT along the Sunda Arc originally tostudy the area of the great earthquake and tsunami of 2004 and is now usedto study the hydrocarbon potential of these forearc basins. The data show bright spots above potential hydrocarbon reservoirs incarbonate platforms. In addition, surface geochemical prospecting indicatesthermal hydrocarbon generation within deep sediment strata. Basin modellingconducted in one of these basins (Simeulue Basin) indicates an activepetroleum system and petroleum charge of the carbonate buildups. For comparison, the petroleum potential of the Sandino forearc basinoffshore Nicaragua has been investigated by means of petroleum systemmodelling. Results revealed that two formations contain sufficient quantities oforganic matter for an effective hydrocarbon generation. Especially in thecentre of the basin these formations were buried deep enough.Coarse-grained deep-water turbidites and shallow-water carbonate rocksmay serve as reservoir rocks.These two examples of different forearc basins show that deep burial ofsource rocks can compensate for low heat flow and each forearc basinshould be studied carefully to evaluate its hydrocarbon potential.Consequently, forearc basins are frontier areas of future oil and gasexploration and production.
19th WPC preprint paper. For delegate use only. Do not circulate.