Hydrocarbon Potential of the Beetaloo Basin, Northern Territory, Australia

Abstract

The Beetaloo Basin, located approximately 500 km southeast of Darwin, NT, is a broad intracratonic basin with Mesoproterozoic and younger sediments. The basin has more than 3000 m of sedimentary fill with thick, world-class source rocks. The richest interval, the Middle Velkerri shale, has 140 m of black shale with typical TOC contents from 4 to 7 %. Basin modeling has shown that these source rocks have produced very large amounts of hydrocarbons. Three thick sandstone reservoirs have been documented by the limited amount of drilling in the Basin. These sandstones are interbedded with the rich source rocks and have had shows in several of the stratigraphic tests that have been drilled in the Basin. Fractured shales and tight gas sands also provide possible targets in the basin. Sweetpea Corporation Pty Ltd has acquired EPs 76, 98, 99 and 117 within the Beetaloo Basin. These permits cover most of the deep basin, the axial Arnold Arch, and the basin margin highs. Initial exploration has been conducted in 2004 with a review of the available data, new basin modelling, and an evaluation of the available seismic, including reprocessing to determine the possibility of improving the data quality. This work has provided a revised interpretation of the hydrocarbon potential of the basin.

New structural maps were generated through the reprocessing of the 2D seismic data, which reveal that few of the wells drilled by Pacific Oil and Gas were located on adequately defined closures. Large untested structures have been mapped based on reinterpretation of seismic and gravity.