Emissions from closed-out boreholes and wells

Queensland has strict conditions that companies must follow when plugging and abandoning exploration and production boreholes and wells.

All new and current coal, petroleum and gas boreholes, wells and associated facilities must comply with rigorous design standards, safety obligations and governance programs set out by the Queensland Government.

The holders of resource authorities are responsible for managing and properly closing out the boreholes and wells they drill. They must undertake activities throughout the entire life cycle of the well or borehole that will prevent future emissions. This includes requirements to cement casings, isolate aquifers and install cement plugs during abandonment.

Coal activities

Any company undertaking authorised coal activities is required to state the location and type of all boreholes drilled. Requirements for abandoning a coal borehole are also listed on the environmental authority issued under the Environmental Protection Act 1994, and under s.100 of the Coal Mining Safety and Health Regulation 2017.

The Queensland Government is currently reviewing the compliance programs for regulating coal exploration boreholes.

Petroleum and gas activities

Boreholes and wells drilled for petroleum and gas activities must be closed out according to the requirements of the Petroleum and Gas (Safety) Regulation 2018. This includes sealing a borehole or well with cement to isolate it from any aquifer or porous formation it intersects. For more information, see the technical information and guidelines on safety issues for petroleum and gas.

Coal seam gas wells and boreholes are also subject to the Code of practice for the construction and abandonment of coal seam gas and petroleum wells and associated bores in Queensland (PDF, 847KB).

The Petroleum and Gas Inspectorate has developed a compliance plan, which outlines the program of work associated with the review and inspection of the construction and abandonment of petroleum wells and boreholes.

Petroleum and Gas Inspectors conduct these reviews and inspections.

Legacy boreholes

Legacy boreholes are historic holes or wells on land where the tenure has now ended or changed. These boreholes and wells have not been constructed by the current resource authority holder and are not owned by them.

The risk of emissions from these boreholes is generally low and the presence of methane gas in mineral boreholes is rare.

Legacy boreholes drilled before the current robust regulatory framework are best dealt with as any issues arise and on a case-by-case basis. Each legacy borehole presents unique conditions that are determined by a number of factors, including the standard to which the legacy borehole was constructed and closed out.

Managing incidents in legacy boreholes

Any incidents will be managed using the Protocol for managing uncontrolled gas emissions from legacy boreholes (PDF, 339KB).

The protocol contains the steps that government and industry must take to deal with fires and unacceptable levels of methane emissions from legacy boreholes.

The steps in the protocol were designed to ensure timely, effective and safe outcomes.