1.2.3 Proposals and exploration


Coal exploration is not actively being pursued in the Gwydir subregion. Therefore no proposals or exploration for coal can be reported here.

There are currently no proposals for coal seam gas (CSG) development in the Gwydir subregion and no reserves have been booked (as of September 2014). However, some initial exploration for CSG has occurred, which has resulted in combined contingency resources (quantities of petroleum that are estimated to be potentially recoverable from known accumulations, but which are not currently considered to be commercially recoverable) of 991 PJ in the subregion.

In the north-eastern part of the subregion exploration for CSG has occurred in the Middle Jurassic Walloon Coal Measures, which were not found to have potential for commercial CSG production.

In the central and central-western Gwydir subregion coals of the Early Cretaceous Bungil Formation have been explored. The coals were undersaturated with mean gas contents of approximately 4 m3/t (dry ash free basis, methane content greater than 93%), a net coal thickness of up to 4.6 m, and low reservoir permeability.

The Middle Triassic Moolayember Formation has been a CSG target in the central-eastern subregion. Results from three exploration wells indicated a mean gas content of more than 4 m3/t (dry ash free basis, no gas composition reported) and a net coal thickness of 3.3 to 8.5 m. Drill stem tests indicated low permeability of the Moolayember Formation.

Further south, in the Bellata Trough region, the CSG potential of the Moolayember and the Bungil formations as well as the Late Permian Black Jack Group and the Early Permian Maules Creek Formation have been assessed. Here the Moolayember and Bungil formations were not found to contain gas volumes of commercial significance. Results from an exploration well targeting the Hosskisons Coal of the Black Jack Group and the Bohena Seam of the Maules Creek Formation were reported as having a net thickness of 2.3 m and a gas content of 5.6 m3/t for the Hoskissons Coal (more than 90% methane) and a net thickness of 14.8 m and a high gas content of 14.2 m3/t for the Bohena Seam. However, the gas consists of more than 80% carbon dioxide. Reservoir permeability was indicated to be low for both coal seams.

CSG exploration and commercialisation in the Gwydir subregion must be consistent with the CSG regulations and exclusion zones that apply in NSW. These zones prohibit new CSG exploration and development within a 2 km buffer of existing and future residential areas.

Last updated:
5 January 2018