ABSTRACT: The buried fold-thrust belt of Offshore Seram

Sykora, Jerry J. , Canadian Petroleum Indonesia, Jakarta, Indonesia

During the Triassic and Jurassic, the isolated outer shelf regions of the northern leading-edge of the Australian craton evolved a carbonate setting distinct in a number of ways from the typical clastic dominated Australian northwest shelf, most notably in its oil prone nature. This Mesozoic oil prone setting extends along tectonic strike within the Australian-Banda boundary complex, from Timor to Buton, with the petroleum system best manifesting itself on the islands of Buton, Buru and Seram. During the Tertiary, tri-plate convergence of the Australian, Eurasian and Pacific plates resulted in varying degrees of structural modification of the Mesozoic section in the outboard regions of the Australian craton. Most relevant to Offshore Seram was the shortening and tectonic thickening of the Mesozoic section proximal to subduction and obduction along the Inner Banda Arc. This orogenic event thermally matured the Mesozoic section through tectonic thickening and deposition of a thick syn-orogenic section, while contemporaneously forming hangingwall rollovers in large thrust complexes and regionally fracturing the thick Manusela carbonate which acts as the primary reservoir in the immediate area. The buried fold-thrust belt of Offshore Seram is ideally positioned within the Seram orogenic complex for preservation of the petroleum system evident onshore Seram through numerous oil seeps, shallow production and recent discoveries by Kufpec. Subsurface imaging of this setting has generally proven impractical with 2D seismic and a recent 3D seismic survey provides insights into not only the structural dynamics but also the vast petroleum potential of this unique setting.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia