Using Potential Field Data for Petroleum Exploration Targeting, Amadeus Basin, Australia

Abstract

The Amadeus Basin, a large Proterozoic basin located in central Australia, is the least explored onshore petroleumbearing basin with proven reserves in Australia. The size and remoteness of the Amadeus Basin makes ground exploration expensive, but airborne gravity and magnetic surveys have been shown to be capable of resolving intra-basin structures in sufficient detail to allow prospective areas to be identified. In the western part of the basin the Gillen Petroleum System is considered most significant: This system has the important characteristic that the source is stratigraphically higher than the reservoir. Thin skinned deformation is expected at the source level and above, with detachments at evaporitic horizons, but deformation of the reservoir is expected to be thick-skinned. This model can form the basis for predicting potential field responses. The most prospective areas are where (i) gravity suggests basement (and reservoir) is shallow, (ii) magnetics maps fold-thrust complexes (structural trap), (iii) these features occur adjacent to gravity lows, indicative of significant thicknesses of basin fill (source at depth and below reservoir). Faults at the margins of the depocentre (mapped using magnetic data) provide a possible migration path for the hydrocarbons.