Publications

Hydrocarbon exploration in Eastern Indonesia is still an immature and is a challenging area, except for relatively mature basins such as Bintuni, Salawati and Banggai, because of geological complexity including veiled tectonics and geology. The offshore Tanimbar region, one of the typical immature areas is located in the Southern Banda Outer Arc and is characterized by collision and obduction zones with elements of the Australian Continental Plate, comprising fold-thrust-belt of the Australian passive margin sequences. Hydrocarbon prospectivity of the offshore Tanimbar region is as yet not well known due to the limited data. In contrast, the adjacent Northern Bonaparte Basin on the Australian Plate is a mature petroleum province with proven gas prone petroleum systems in the Upper Palaeozoic to Mesozoic. This paper presents new insights into the hydrocarbon prospectivity of the frontier offshore Tanimbar region based on exploration studies in the Babar Selaru block. Widespread occurrences of oil and gas seeps are confirmed in Eastern Timor Island including thermogenic hydrocarbon migration to the seabed as confirmed by seabed cores in the offshore Tanimbar region and by oil stains in outcrops in the Tanimbar Archipelago. The origin of these hydrocarbons is mostly interpreted to come from a Late Triassic-Jurassic source. Recently acquired high quality 3D broadband seismic data in the Babar Selaru block has revealed the detailed architecture of thrust deformation of the Australian passive margin sequences in the region. The geologically plausible architecture of imbricated thrusts and its geological history were developed in this difficult to interpret area through a 2D/3D structural restoration study. This model explains well the expulsion of oil from the uplifted Late Triassic-Jurassic source rock and its migration to the Miocene thrust anticline traps. A similar oil prone petroleum systems have been confirmed at the Tiaka oil field in the Banggai Basin, Sulawesi. This paper discusses the possibility of the Neogene oil prone petroleum systems along the Banda Outer Arc as well as in the offshore Tanimbar region. Keywords: Banda Arc, Fold-Thrust-Belt, Late Triassic-Jurassic Oil Prone Source Rock, Miocene Carbonate Reservoir