Unlocking Potential for Unconventional Petroleum Resources in the Frontier McArthur Basin, Northern Territory, Australia

Abstract

Significant potential for unconventional hydrocarbon resources exists in the vastly underexplored Proterozoic source rocks of the McArthur Basin, which is poorly exposed over a large proportion of the Northern Territory, Australia. Recent advances in technologies for liberating hydrocarbons from shale have now made exploration feasible in remote, frontier basins such as the McArthur Basin. For this reason the Northern Territory has seen a significant increase in onshore exploration for unconventional resources over the last two years, with a focus in the McArthur Basin. The Northern Territory Geological Survey (NTGS) is currently assessing the McArthur Basin for its hidden potential for self-sourced continuous shale plays. New data has emerged from historical wells that were deemed unsuccessful for conventional oil and gas plays at the time of drilling. This data combined with the application of new analytical techniques, approaches and ideas to the understanding of the regional-scale geology and basin architecture could unlock a potential for unconventional plays that had been previously overlooked in the McArthur Basin. Recent and ongoing work by the NTGS is focussing on the Mesoproterozoic black shales of the Roper Group, within the Wilton Package of the McArthur Basin. The Roper Group comprises two prospective shale units, the Kyalla and the Velkerri formations. Both formations have proven potential as active source rocks, with oil shows being documented for each unit in a number of wells. The result of this assessment will be a compilation of data sets and 2D sub-surface maps using the geological evaluation standards for high shale gas production and accumulation areas. 2D subsurface maps will include total organic carbon (TOC), brittle and clay mineral content, shale maturity, kerogen typing, effective thickness, depth of formation, and fluid and gas content. Recent exploration has resulted in a number of technically successful wells intersecting the shales within these packages, which has paved the way for further innovative drilling across the basin. The next phase of the investigation will see the repetition of the shale evaluation throughout the Meso- to Palaeoproterozoic packages, and to form a basin-wide overview of the unconventional petroleum potential of the McArthur Basin.

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015