Publications

Situated in the centre of the Salawati Basin, it is almost certain that the Tertiary Klasafet Formation and its equivalent formations are the source rocks of the Kais reservoir at the Arar and Walio Areas. Hydrocarbon generation and expulsion occurred in the Pliocene and migrated to the nearest Kais Formation carbonates. The Tertiary Kais carbonate play has been successful and several deeper wells were drilled to explore other petroleum systems within the pre-Kais and pre-Tertiary intervals. This paper provides insights of the source rock potential of the pre-Kais sediments in the Arar Area, the Permo-Triassic Aifam Group and the Late Jurassic � Late Cretaceous Kembelangan Formation in the Walio Area. Wells in the Arar Area encountered thin pre-Tertiary sediments. This interval is thickening towards the Walio Area in the south, where the Jurassic � Cretaceous sediments are mostly eroded. Basal heatflow is high in the north and decreases to the south, presumably due to the proximity to the Sorong Fault Zone. Burial history and thermal maturity models (1D basin modeling) were constructed to understand the timing of hydrocarbon generation. In addition, 3D basin modeling provides information of hydrocarbon migration pathways and accumulation. The type-III kerogen of the pre-Kais source rocks in the Arar Area is in the stage of late to post mature. High TGAS in the pre-Kais formations could indicate a working petroleum system. The hydrocarbon expulsion and migration of the pre-Kais potential source rocks occurred during Pliocene to recent. Maturity of the Permo-Triassic Aifam Group in the Walio Area is peak to post mature in the western part. The Late Jurassic � Late Cretaceous Kembelangan Formation is gradually post mature towards the west. Both potential source rocks are type-III kerogen. Main expulsion from the Aifam Group occurred in the Cretaceous. The petroleum system main risks are the extent and quality of potential source rocks and preservation of the migrated hydrocarbon.