The information in this section was obtained from various water management plans produced by AGL Energy Limited (AGL; AGL Energy Limited, 2012, 2014b, 2014c, 2015), produced water factsheets () and AGL’s review of environmental factors for the Waukivory Pilot Project ().
During the fracture stimulation of a CSG , the volume of water required for fracture treatment is estimated to be between 0.9 and 2.4 ML per well and 100% of flowback water and 0.5 L/s per well of produced water are estimated to be generated. Produced water volumes per CSG well are expected to be maximum at the commencement of fracturing/testing but to quickly diminish to much lower volumes (typically an order of magnitude lower, Figure 21) (). As part of the Gloucester Gas Project, AGL is planning to treat produced water using reverse osmosis, a desalination technology to reduce the amount of salt in the produced water and to be used for irrigation or returned to the environment (). AGL is planning to store the water in dams on Tiedmans Property (Figure 22) or in on-site storage tanks.
AGL Upstream Investments Pty Limited (AGL) has the following water management plans for the Gloucester Gas Project area:
The irrigation areas are located on Tiedmans Property at Stratford about 9 km south of Gloucester (Figure 22). The irrigation period is expected to be 18 to 24 months but may extend to 36 months depending on the final volume of produced water from exploration program . The proposal is to irrigate a volume of 70 ML of the produced water in storage over a maximum area of 40 ha over three years. This will include (i) water from exploration programs that is already stored in the Tiedman and Stratford dams, (ii) any rainfall that falls in the dams and (iii) any additional produced water from 2012–2014 exploration activities. This water will be blended with water from the Avon River at a ratio of about three parts river water to one part produced water, to optimise water quality of the irrigated water. The storage dams (Tiedman north, Tiedman south and Tiedman east) are of a ‘turkey’s nest’ style construction with a capacity of 20 ML each (Figure 22). Tiedman south dam is the primary blended water irrigation dam, whereas Tiedman north and Tiedman east dams are used for storing the untreated water pumped during CSG operations.
Two dams were constructed to capture from the trial area during larger rainfall events. There will be no irrigation on the alluvial floodplain soils where there are potential pathways for the irrigated water to flow to the shallow and the Avon River ().
AGL holds seven licences under NSW’s Water Act 1912 for the commercial/industrial /irrigation reuse of pumped during flow testing programs with total volume of 35 ML/year. AGL also holds a water access licence (WAL 19521) and works approval (20CA204347) to extract 32 ML/year from the Avon River source adjacent to the site for irrigation. This fresher will be blended with the stored produced water for irrigation of salt tolerant crops.
Full-scale CSG operations in the have not been developed. However, AGL has been conducting CSG exploration program under the name of the Waukivory Pilot Project. Further information about this project is provided in the Section 126.96.36.199.1 of companion product 1.2 for the Gloucester subregion ().
The Waukivory Pilot Project involves the fracture stimulation and testing of four gas concurrently (WK11, WK12, WK13 and WK14). The maximum volume of flowback water and produced water likely to be pumped for the four gas wells is 20 ML over the life of the program (14 ML of produced water and 6 ML of flowback water). The volume of water required for fracture treatment is estimated to be between 0.9 ML and 2.4 ML per well and around 6 ML in total for the whole fracture stimulation program expected to be completed by end of 2015. Water for hydraulic fracture stimulation will be sourced from licensed water supply works from either Pontilands (expected allocation is 20 ML per annum) or Tiedman dams, located on nearby properties owned by AGL. The on-site water management involves (Figure 23):
- water gathering lines from pilot wells to the water staging point at WK13
- storing water in dual lined dams at WK13 and monitoring storage levels
- monitoring the salinity of the flowback water
- transportation of flowback water for lawful disposal at an appropriate facility
- monitoring the salinity of the produced water
- transporting produced water via water pipeline or trucks to the Tiedmans Property for storage, blending and reuse (after treatment) for industrial/irrigation/stock/stream disposal.
- storage of produced water from AGL’s offsite operations and transport of this water within the Tiedmans Property
- blending of produced water with freshwater for irrigation reuse, subject to the water quality meeting relevant Australian and New Zealand Environment Conservation Council (ANZECC) criteria, a water quality guidelines
- storage for blending and/or direct reuse for stock use, subject to the water quality meeting the relevant ANZECC criteria
- storage for blending and/or direct reuse for industrial uses such as fracture stimulation, dust suppression and firefighting, subject to water quality meeting the relevant ANZECC criteria
- storage for future drilling and hydraulic fracture stimulation purposes.
It is proposed to reuse all produced water from the Waukivory Pilot Project unless the water quality exceeds a pre‐blending salinity (i.e. electrical conductivity (EC)) of 15,000 μS/cm. The produced water would be blended with fresh water sources (mostly river water) to obtain a blended water mix (i.e. with a salinity level of up to 2000 μS/cm) suitable for irrigating salt tolerant crops. Produced water, flowback water and natural from the Waukivory Pilot Project are stored on site in above-ground tanks (75,000 L capacity) or open-top tanks (40,000 L capacity) and then transferred by road tanker to the Tiedman dams for either industrial use or blended water irrigation. AGL is planning to treat produced water using a desalination technology, reverse osmosis, to reduce the amount of salt to an acceptable level for irrigation or for returning (a portion of treated water) to the environment during the floods ().
Product Finalisation date
- 2.1.1 Geography
- 2.1.2 Geology
- 2.1.3 Hydrogeology and groundwater quality
- 2.1.4 Surface water hydrology and water quality
- 2.1.5 Surface water – groundwater interactions
- 2.1.6 Water management for coal resource developments
- Currency of scientific results
- Contributors to the Technical Programme
- About this technical product