Publications

The Buton area has long been known to have large asphalt deposits and has been in production for a long time. The asphalt deposit is an oil field that has been uplifted resulting in its cap rock to be eroded and the oil that it contained to be degraded into the asphalt. There are also many oil and gas seeps identified in the Buton area, proving the presence of active petroleum system(s). Hydrocarbons have been formed, migrated, and trapped in the Buton area; therefore, oil and gas fields could be found in Buton. Previous exploration wells failed due to the complicated geology and structural problems, caused by poor seismic data and challenging subsurface imaging. Those wells also often did not reach their objectives or were off structure. Buton has a long tectonic and stratigraphic history since it was once part of the northern edge of Gondwana. This includes rifting, drifting, collision to SE Sulawesi, and post-collision episodes. Each episode formed its own petroleum system elements and/or processes that could be important for the development of accumulations. Using a play-based exploration method, this study has resulted in new insights into the petroleum prospectivities of Buton. New reprocessed gravity data show several low areas where petroleum generation may have occurred and basin modelling was carried out in these prospective kitchens. Based on geochemical data from the Mesozoic to the Miocene sections, several source beds are present, comprising various organo-facies sources from terrestrial, transitional and marine origins. The tectonic and stratigraphic histories formed several play types: paleo structure-carbonate build-up plays associated with passive margins, Australian fold-thrust belt play associated with the collision, and strike-slip fault play associated with post-collisional deformation. Tens of structural leads with multiple reservoir targets have been identified, mapped and volumetrically quantified. The study concludes that Buton remains of strong interest for exploration and that the new insights and mapped leads provided by this study are worth considering for further exploration activities in the Buton area.