2.1.6.11 Narrabri Gas Project (ACRD)

The Narrabri Gas Project is currently in the preliminary stages of environmental approval. Santos Ltd has submitted a preliminary environmental assessment (PEA) to the NSW Department of Planning and Infrastructure (GHD, 2014), which proposes to develop the CSG reserves in the Narrabri area. The project has also been referred for assessment under the Commonwealth’s Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), and will require Commonwealth approval. There is relatively limited information available in the public domain relating to the project, as the environmental impact statement and supporting studies are currently being prepared. It is noted that the Narrabri Gas Project Environmental Impact Statement was released in early 2017 and will contain updated information about the proposed water management strategy for the project. However, these details were not available to the Assessment team at the time of writing and consequently are not reflected in this section.

The targeted coal seams for the project are primarily in the Maules Creek Formation (GHD, 2014). The proposal is to develop a gas field with up to 850 production and appraisal wells, as well as an integrated gas and water gathering system. The proposed gas field would include:

The Narrabri Gas Project area covers about 98,000 ha including several state forests and private land. It excludes the conservation area and nature reserves of the Pilliga woodlands. The proposed field operations will take up approximately 900 ha mostly in the Pilliga Forest. The Narrabri Gas Project could produce 200 TJ (terajoules) of natural gas per day, which would be transported via a new pipeline connection running south from Narrabri (GHD, 2014).

For the Narrabri Gas Project, estimated peak water production is approximately 2920 ML/year, which is forecast to stabilise at around 1460 ML/year approximately 10 years after production commences (Santos, 2012). The produced water and brine is intended to be first stored in ponds and then treated – typically by desalination using reverse osmosis or through amendment by altering the chemical balance of the water. The selection of the treatment process will depend on the original water quality and the intended use of the treated water (Santos, 2012).

Santos currently has no plans to use hydraulic fracture stimulation on future wells drilled as part of the Narrabri Gas Project, as geological data indicates that hydraulic fracturing would not increase gas flows in the coal seams (Ecological, 2014).