Working on plugging decommissioned oil and gas wells with bentonite (naturally occurring clay), Professor Brian Towler’s team from the UQ Centre for Coal Seam Gas (CCSG) and School of Chemical Engineering has recently been awarded a $175,000 Advance Queensland Grant.
At the moment, coal seam gas (CSG) wells and all oil and gas wells are required to be plugged with cement, however, bentonite technology will potentially create more reliable plugs in terms of longevity. Over the coming decades, the need for plugging decommissioned wells in Queensland will increase considerably as the number of CSG wells has multiplied in the past decade.
The “Low emission bentonite well plugs” project will run for two years and investigate the performance of bentonite plugs in Australian conditions. The funding will support additional research to develop optimised material compositions and new plug-geometries for a wider range of older, legacy wells from coal, CSG and agricultural industries.
This could include stratigraphic/exploration wells from the coal industry (open ‘coal holes’) and a way to repair or seal sections of damaged casing to improve the protection of essential groundwater resources and potentially reduce methane emissions.
The project will be led by principal research fellow Dr Heinz-Gerd Holl and is supported by four of Australia’s large coal seam gas companies, Shell, Arrow Energy, APLNG and Santos, through CCSG.