Prospective shale gas resources are hosted in the Paleoproterozoic rocks of the Isa Superbasin in north-west Queensland. The limited exploration of the region to date has focused on the northern Lawn Hill Platform where extensive organic-rich shales occur, and where shale gas flowed from a hydraulically stimulated well near Burketown. However, further exploration and appraisal remains needed to improve knowledge of the shale gas resources, ahead of any future gas development.
Prior to any potential gasfield development, it is critical to adequately understand the regional hydrology and ecology. Future gas development may potentially impact groundwater and surface water, and the natural and human ecosystems that rely on these resources. Consequently, enhancing our baseline knowledge of the region's hydrology is necessary to help assess the availability of groundwater resources, the scale and complexity of surface water-groundwater interactions, and the potential hydrological connections between gas reservoirs and aquifers.
The Australian Government's Geological and Bioregional Assessment (GBA) Program aims to assess potential impacts of shale and tight gas development on water and the environment in three onshore areas (Cooper, Isa and Beetaloo regions). The initial phase of multidisciplinary research for the Isa GBA has improved our baseline hydrological conceptualisation. This area is host to two major groundwater systems. The deeper system exists within the Proterozoic Isa Superbasin and overlying South Nicholson Basin. A shallower and more widely utilised groundwater system (tapped by over 80% of local bores) is hosted within aquifers of the Jurassic-Cretaceous Carpentaria Basin, and overlying Cenozoic Karumba Basin, collectively part of the Great Artesian Basin (GAB).
The improved baseline knowledge of groundwater and surface water systems has identified a number of knowledge gaps, including the potential for connectivity between the two groundwater systems. It has also informed the development of a future sampling regime that could be used to help address the identified data gaps.