Publications

Tectonically, the Salawati Basin is defined as a Cenozoic foreland basin with a wedge top area on the northern part, bounded by the Sorong Fault Zone, and an E-W-trending elongate foredeep with aforebulge area uplifted in the eastern part. In the western part lies the Kofiau sub-Basin which has been discussed in a number of publications since 2014, with the main exploration activities focused on the Pliocene Klasaman sands, rather than the Miocene carbonate build-ups which are the main target plays in the main Salawati Basin. Two exploration wells have already confirmed this Pliocene play in the Kofiau sub-Basin (Ajek-1 and Elit-1), but the results were not encouraging. Since then, there has been no detailed study about the Kofiau sub-Basin, nor its correlation with the Salawati Basin and implications to hydrocarbon potential. In this study, using mainly satellite gravity data, well data from his, and 2D regional composite seismic lines, we attempt to define the regional basin outline in order to correlate petroleum play concepts between the two basins. Satellite gravity data have been processed using bandpass filter, in order to divide regional and residual gravity anomalies. The regional gravity anomaly map clearly defines the Bintuni and Salawati Basins as relatively deep, when compared to the Berau Basin, which the residual gravity data shows as relatively shallow. The interpretations presented in this paper suggest that the Kofiau sub-Basin is corresponds to the deepest part of the Salawati Basin. This conflicts with previous interpretations that state the deepest part of Salawati Basin is in the northern area, bounded by Sorong Fault Zone. An E-NW-trending 2D regional seismic line was used to calibrate the gravity model and clearly confirmed that the deepest depocenter is in the western part of the basin, and is cross-cut by the Sorong Fault Zone. This new interpretation has implications on the location of the kitchen and associated migration pathways of the Salawati Basin.