In 2016, AGL announced that exploration and development of upstream gas assets will no longer be a core business for the company due to the volatility of commodity prices and long development lead times.

How AGL decommissions coal seam gas wells

Since early 2016, we've progressed with the extensive decommissioning and rehabilitation program for our wells and infrastructure in the Gloucester region. We're also progressively decommissioning wells and rehabilitating sites at the Camden Gas Project prior to ceasing production in 2023.

The decommissioning of coal seam gas wells is done in line with the NSW Government's Code of Practice for Coal Seam Gas to ensure that it is completed safely without risks to health or the environment.

The code of practice requires that coal seam gas 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 requires that:

  • the well-head equipment is removed,
  • the subsurface water is kept isolated from the coal seams,
  • the coal seams are isolated from other aquifers,
  • 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 Coal Seam Gas Well Integrity (no brackets), is place 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 operator, the well depth and when it was decommissioned, is welded to the top of the casing.
  • The decommissioning works are overseen by the Department of Planning & Environment (DP&E) and the Environment Protection Authority (EPA) Gas Regulation branch, and conducted within stringent health, safety and environment guidelines. A full report is provided to the regulator once all decommissioning works have been completed.

Step 1 - A workover rig set up on the site

The rig will be set up on the site for up to four weeks.

 

Step 2 - Non-perforated case well

A purpose-designed cement slurry is placed to full depth in stages and allowed to set, filling length of entire well.

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Step 2 - Perforated case well

The first 200m-long cement plug is injected and allowed to set for at least six hours. It is then pressure-tested before adding the next cement plug. Cement then placed in additional stages to full depth and allowed to set.

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Step 3 - Finishing the well casing

Well casing cut to at least 1.5m below ground level. An information plate is welded to well casing, sealing it. This data is sent to relevant government agencies.

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Step 4 - Site rehabilitation

Initial rehabilitation returns the surface of the site to the original contour of the land, usually seed is sown, or as agreed with the landowner.

Rehabilitation then continues over 12-18 months until both the regulator and landowner are satisfied.

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Community Complaints and Enquiries 

If you would like to enquire or make a complaint about the Gloucester or Camden Gas Projects, please feel free to contact us via the following channels:

AGL Community Complaints & Enquiries Hotline: 1800 039 600

Email: AGLCommunity@agl.com.au

Mail: AGL Community Complaints & Enquiries, Locked Bag 3013, Australia Square NSW 1215

You can find out more about how AGL engages with the community here.


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