Camden Gas Project

Natural gas was extracted from coal seams throughout the Macarthur region of New South Wales, located about 65 kilometres south-west of Sydney, within the Camden, Campbelltown, and Wollondilly local government areas.

Collected via low pressure underground gathering lines the gas was compressed, dried and made ready for use by households and businesses at the Rosalind Park Gas Plant. The plant has now been decommissioned, equipment was removed, hardstand demolished and the site has entered the rehabilitation stage.

The 144 wells are being progressively decommissioned, and the sites rehabilitated.

Decommissioning requires the use of a ‘Workover Rig’ (pictured to the right) and some auxiliary equipment on site. No drilling or fracture stimulation (‘fraccing’) occurs during decommissioning.

How AGL decommissions coal seam gas wells

Decommissioning and rehabilitation is undertaken with a high level of regulatory oversight by the NSW Government’s Department of Planning and Environment, Department of Regional NSW and the NSW EPA as lead regulator, and to standards set in the NSW Government’s Code of Practice for Construction, operation and decommissioning of petroleum wells, found here.

The code of practice requires that petroleum well decommissioning ensures “the environmentally sound and safe isolation of the well, protection of groundwater resources, isolation of the productive formations from other formations, and the proper removal of surface equipment." The code of practice and petroleum production lease conditions require that:

the surface equipment is removed,
the subsurface water aquifers are kept isolated from each other and from the coal seams (hydrocarbon zones),
risk to future mining of the coal seams is minimised.

Coal seam gas well rehabilitation

In rehabilitating its well sites, AGL will ensure:

The equipment at the top of the well is safely removed.
Purpose-specific cement, which complies with the standards set by the NSW Government’s Code of Practice for Construction, operation and decommissioning of petroleum wells, is placed inside the well from bottom to top in stages.
This cement seals the wellbore and adds to the integrity of the well.
The well casing is cut off, at least 1.5 metres below the surface, so that it does not interfere with agricultural and other future land uses. A steel cap, containing data such as the name of the well, the well depth and when it was decommissioned, is welded to the top of the casing.
The decommissioning works are overseen by the NSW Department of Planning & Environment (DP&E) and the NSW Environment Protection Authority (EPA) which is the lead regulator for petroleum activities in NSW, and conducted within stringent health, safety and environment guidelines. A full report is provided to the regulator once all decommissioning works have been completed for each well.

The rig is usually set up on site for approximately 2-3 weeks.

The first 200m-long cement plug is injected and allowed to set until it reaches minimum compressive strength as set by the NSW Government’s Code of Practice (usually overnight). It is then pressure-tested before adding the next cement plug. Cement is then placed in additional stages to fill the well and allowed to set.

The Well casing is cut to at least 1.5m below ground level. An information plate is welded to well casing, sealing it. A full report on each decommissioned well is sent to relevant government agencies. The locations of decommissioned wells are kept on a live map at MinView website maintained by Department of Regional NSW, Mining, Exploration and Geoscience available at Minview.

Community complaints and enquiries

AGL understands that we don’t always get it right, and we want to be informed when we don’t. If you would like to provide any feedback, good or bad, or simply ask some questions, please feel free to get in touch via the following channels: