Water reuse in coal seam gas

The rise in CSG developments and associated infrastructure in Australia presents numerous opportunities for the water industry.

With reserves of CSG in Australia estimated to be in excess of 16,000 Petra Joules (PJ), producers are looking to innovative solutions to address potential water management challenges.

GHD Principal Process Engineer Kostas Athanasiadis explains, “Large volumes of water are generated as part of the CSG extraction process, known as Associated Water (AW) or as Produced Formation Water (PFW). Salinity of the AW needs to be addressed before reuse of the water can be considered.”

GHD is working closely with all four major CSG advocates to design the required infrastructure and facilities for treatment of the annual estimated 100 GL of CSG AW in Australia. Integrated solutions for the initiative include current and emerging desalination technologies, blending and amendment systems to maximise reuse and reduce desalinating costs, and evaporation/crystallisation technologies to achieve zero liquid discharge, reducing the potential impact on the environment.

Kostas adds, “Some CSG producers are looking to use this excess water for their own irrigation schemes or for use in servicing mine requirements (after purification).

“We are currently modelling scenarios in Water reuse in Coal Seam Gas for aquifer recharge and are looking at sending purified water directly to surrounding farms for irrigation, thereby indirectly replenishing stocks of groundwater by reducing farm use, or by pumping treated water directly into the groundwater table.”

Application in aquaculture and fisheries has also emerged as an area of interest for CSG water, providing an additional boost to local economies in regional areas.

“We are examining all available options,” says Kostas, “Our people are currently involved in research and development projects to assess the feasibility of producing commercially viable salt products such as soda ash and cooking salt from the CSG brine. Additionally, we are involved in engineering designs of regulated waste collection facilities for the management of non-commercial mixture of salts produced during the crystallisation of brine.”

GHD is also providing the relevant civil infrastructure — roads, tunnels, water supply, accommodation and mine design — to CSG producers. We are delivering Environmental Impact Assessments integrated with pipeline design, treatment plant development and combined feasibility, planning and design of pilot facilities (both on-shore and off-shore).

For more information, contact:

Kostas Athanasiadis
Tel: +61 7 3316 3277
Email: konstantinos.athanasiadis@ghd.com.

This abridged story appeared in GHD News 135. Click here to view the entire story.

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