A successful marriage of science, technology and old-fashioned hard work could save lives — and livelihoods — at a Newcastle colliery. By Roger Wischusen*

Investment in research can lead to rewards in areas other than those originally targeted. ACARP has supported several projects in recent years that have contributed to success in addressing a significant challenge at the Moonee colliery, near Newcastle in New South Wales.

Strata Control Technology Pty Ltd and CSIRO Division of Mining and Exploration were supported by ACARP in a project, “Improved Assessment for Ground Behaviour Around Longwall Faces”. This project won the 1998 ACA Excellence in Research Award of Best Underground Research Project.

ACARP also supported Dr Rob Jeffrey at CSIRO’s Division of Petroleum, Melbourne, in his attempt to increase the gas flow from some gassy coal seams using hydraulic fracturing, a technique widely used in the petroleum industry for stimulating reservoirs.

Moonee, operated by Coal Operations Australia Ltd (COAL), was hit by interruptions to production due to significant windblast events. A team headed by COAL chief geologist John Edwards implemented a leading edge micro-seismic monitoring strategy to improve the accuracy of forecasting the windblasts events. This system has been highly successful over recent longwall panels but COAL has continued to seek techniques to control caving events to complement the predictive capability.

Dr Ken Mills of Strata Control Technology (SCT Operations), Dr Rob Jeffrey of CSIRO Petroleum and Mr David Jones of COAL coordinated a multi-faceted investigation and initial trials using the combined resources of the three organisations to induce a caving event “on demand” using hydraulic fracturing. The work culminated in a favourable outcome on the first application of the technique on June 30, 1999, when about 70,000 tonnes of conglomerate strata was induced to fall during a treatment that lasted two hours. The risk of windblast was eliminated by the treatment during a period when men were withdrawn from the longwall face.

Treatment of the ground using hydraulic fracturing has been practised at various locations in the past with mixed success. The Moonee project marked the first time hydraulic fracturing had been used in a coal mine to induce a goaf fall “on demand”

The successful outcome of the project is the result of the commitment of the colliery management to a strategy of developing understanding using scientific investigation, full scale trial, and refinement by ongoing measurement. The integration and refinement of hydraulic fracturing as a tool to control windblast into the overall mining strategy will be an ongoing process.

As the colliery’s technical services coordinator Shaun McDonell commented after the event: “It was truly wonderful to see the concerted application of science to the solution of an engineering problem.”

This experience highlights the upside of scientific research activity and ACARP’s role in keeping the industry focused on the range of rapidly advancing technologies available.

* Roger Wischusen is manager of Australian Research Administration Pty Ltd, which administers the ACARP program.