Session 12. Oral Presentation for: Field trials of bentonite as abandonment material for underground coal gasification wells in Queensland, Australia

Presented on 28 May 2025: Session 12 The decommissioning of wells, particularly in response to the rising environmental and economic challenges, has become an urgent priority globally. In Queensland, Australia, the decommissioning of wells associated with underground coal gasification (UCG) presents unique risks due to the shallow coal formations and potential groundwater contamination. This study explores the efficacy of bentonite as an alternative abandonment material. We present field trials from the Bloodwood Creek UCG facility, involving the abandonment of three wells with bentonite as a primary sealing material. In addition, benchtop tests were completed to evaluate bentonite’s hydration compatibility with field water samples. The outcomes suggest the necessity for specific laboratory testing procedures tailored to bentonite’s unique properties, highlighting its capacity for rehydration and potential sealing capability post-failure. These findings contribute empirical data towards optimising well abandonment methods that address both environmental sustainability and economic feasibility. To access the Oral Presentation click the link below. To read the full paper click here