The Permian gas potential of the Taroom Trough, Queensland: new ideas to unlock a multi-TCF play

Abstract

The Taroom Trough in Queensland is the main synclinal depression and southern extent of the Bowen Basin. Both the Bowen Basin and the overlying Surat Basin have been the focus of Australia’s coal seam gas (CSG) liquefied natural gas (LNG) export industry since 2014, but with CSG production now in decline and with a greater focus on domestic gas, it is timely to review the potential of new plays in this region. Although exploration and development in the Taroom Trough over the past decade have focussed on shallow Permian and Jurassic CSG resources, the early hydrocarbon potential of the trough was realised through conventional discoveries. Regardless of the reservoir, all conventional hydrocarbons in the trough have been typed to the same prolific Permian coals. These source rocks produce enormous volumes of oil and gas, yet only a small percentage of those volumes have been trapped in known conventional structures. This implies that a significant volume of oil and gas could remain trapped in tight reservoirs, including Fractured Thermally Mature Coals. Elixir Energy Limited plans to commence a drilling program in 2023 in ATP2044 (Grandis Gas Project) to unlock the gas potential of the Taroom Trough. The project will investigate the potential of Permian coals and sandstones at >3700 m depth using new understandings developed from recent studies into the critical role of elastic rock properties and stress anisotropy on coal fracture growth. This paper describes the opportunity that Elixir has identified and details the legacy technical work in the area and new research and ideas which have since evolved.