Petroleum Geology of the Onshore Bonaparte Basin

Abstract

The Bonaparte Basin formed in the Early-Mid Paleozoic as a result of divergent left-lateral wrenching within the NE trending Halls Creek Mobile Zone. The main phase of deposition in the onshore portion of the basin occurred in the Late Devonian to Early Carboniferous, when over 5000 m of sediments were laid down. Extensive outcrops around the basin margins demonstrate complex facies relationships and the continuance of wrench faulting during deposition. A NE trending basement high occurs in the eastern Bonaparte Basin. A barrier reef complex is predicted to cap the ridge with sub-tidal and estuarine sediments deposited in the shallow water conditions that existed east of the barrier. Oil shows have been encountered in shallow core holes cdrilled around the basin margins. Source rock analyses have also highlighted the potential of the basinal shales and lagoonal carbonates to be produced hydrocarbons. Gas has flowed on test from thin sands within the Bonaparte Basin Beds in two of the six wells drilled onshore.