Abstract

Exploration for hydrocarbons began on Seram Island during the second half of the nineteenth century following the identification of numerous oil and gas seeps. Although extensive early geological mapping and outcrop studies were carried out, exploration and production of hydrocarbons has, to date, been primarily concentrated in the Cenozoic section of the Bula Basin, north eastern Seram. Recent exploration drilling, aerial surveys, the acquisition of modern seismic data and recent field studies have led to the generation of new geological and tectonic models for Seram and improved prospectivity for the Mesozoic sequence.

A review of all reliable field and well data on the Island has led to the identification of both an early Australian Series (Triassic to Upper Miocene) and a younger Seram Series (Upper Miocene to Recent). The sedimentary sequence within the Australian Series can be correlated to the Northwestern Australian continental margin. Paleo-geographic and tectonic models showing the relationship between Seram and this margin are presented. Pre and incipient-rift (early Triassic and older), syn-intracratonic rift (early Triassic to middle Jurassic), continental breakup (latest middle Jurassic to early Cretaceous) and post-breakup/passive margin (early Cretaceous to late Miocene) sequences are identified similar to those widely studied and described on the Northwest Shelf and in the Timor Sea region. The Seram Series is strongly influenced by the interaction of the Australian, Pacific-Philippine and Eurasian plates from the Late Miocene until the present. This interaction has led to periods of thrusting, uplift and erosion of the Island. The processes active are reflected in the presently observed structural style.

This revision of the stratigraphic and tectonic history has led to a re-appraisal of the prospectivity of the Island and the identification of key factors with regard to pre-Tertiary reservoirs, structural style, hydrocarbon source (Triassic - Jurassic) and migration.