ACARP ACARP ACARP ACARP
Underground

Gas Drainability and Outburst Risk Assessment based on the Distribution of Micro-Markers in Coal Seams

Underground » Ventilation, Gas Drainage and Monitoring

Published: September 03Project Number: C11057

Get ReportAuthor: Andrew Gurba, Lila Gurba, Colin Ward, Jeff Wood | AGURBA, CCSD, University of New South Wales, BHP Billiton Illawarra Coal

Access to underground coal reserves in Australia and other coal producing countries is often conditional on the reduction of coal gas content to below specified regulatory outburst threshold limits. Reduction of gas content is generally achieved by pre-drainage of the coal seam using underground in-seam drainage. Several coal mines in New South Wales and Queensland are encountering areas in which drainage of gas has proved to be very difficult. In many operations local areas of low drainability are a major obstacle in achieving economic longwall gate road development rates.

A recent study funded by ACARP (project C10011) was undertaken to determine the nature and origin of the very low drainability areas within the Bulli coal seam of the southern Sydney Basin. The purpose of the project was to investigate the coal properties affecting gas drainage, and to develop a simple means of detecting areas of difficult drainage well in advance of mining. Detailed petrological study was undertaken on coal samples selected from the Bulli seam at Tower and Tahmoor Collieries in the Southern Coalfield.

The results of the project have shown that some differences in coal properties are directly related to gas drainage efficiency. These differences are related to the presence of some specific micro-markers identified in the difficult drainage areas, particularly to the development of the micro-cleat system and its mineralization, micro-mylonitisation of the coal, the mode of occurrence of particular minerals within coal macerals, the presence of oil and solid bitumen as fracture infills and in coal macerals, the presence of heat-affected coals and the presence of pyrolytic carbon possibly derived from more distant intrusion effects.

This project was undertaken to test applicability of the micro-markers outside the Southern Coalfield of the Sydney Basin, i.e. in the Hunter Coalfield and the Bowen Basin.

Petrographic studies of samples collected from selected coal mines in those areas have confirmed that it is possible to infer the drainability of a coal seam and its proneness to outburst, based on microscopic examination of coal samples. The results of the tests proved that the micro-markers and their influence on coal drainability are not unique to the Bulli seam in the Southern Coalfield. The universality of the micro-markers makes them a very powerful tool in assessing potential gas drainage conditions for future coal mining operations and/or in new coal extraction areas of existing mines.

Identification of the presence of these micro-markers in coal, well ahead of mining, i.e. in exploration and/or development stages of a coal mining operation, will provide a significant input to the effective planning/design/timing of the underground drainage system for any future underground coal mine operations.

The major benefits of the project are the ability to detect areas with difficult and slow drainage characteristics, and also potential outburst prone areas, in advance of development. Applying appropriate drainage conditions will make coal mining operations safer, less prone to outburst and more economically viable.

Underground

Health and safety, productivity and environment initiatives.

Recently Completed Projects

C27010A Clinical, Radiological And Occupational Review Of Coal Mine Dust Lung Disease In Queensland

The aim of this project was to review recently diagnosed cases of Co...

C26061The Young’S Moduli, Poisson’S Ratios And Poroelastic Coefficients Of Coals

This report describes the measurement of coal (and rock) properties ...

C24015 Assessment Of Convergence Based Roof Support Design For Longwall Abutment Loads

The aim of Stage two of project C24015 was to develop a roof support...

Underground

Open Cut

Safety, productivity and the right to operate are priorities for open cut mine research.

Recently Completed Projects

C23029Alternative And Sustainable Explosive Formulations To Eliminate Nitrogen Oxide Emissions

This technical report describes the technology of a novel mining exp...

C25005Site Based Trials Of Alternative Explosive Formulations To Eliminate Nitrogen Oxide Emissions

This report documents the outcomes of Phase 3 of this project and b...

C26022Real-Time Prediction Of Coal Top Through Guided Borehole Radar Wave Imaging For Open Cut Blast-Hole Drilling

Damage to the tops of coal seams caused by incorrect blast stand-off...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C26015Novel Characterisation Of Coal Petrography For Improving The Dewatering Of Fine Coals Using Chemicals

This project aimed to develop alternatives to existing mechanical de...

C26014Low Cost Online Measurement Of Particle Size And Density For Diagnostics Across The Fine Coal Circuit

This project has developed a novel prototype optical system for prof...

C26008Implementation Of Oxidation Monitoring Tools And New Reagents In Plants To Improve The Flotation Of Oxidised Coals

Flotation of oxidized coals is a challenge confronting the Australia...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C26045Mineralogy Effects On The 3D Porosity Evolution Of Coke And Coke Reactivity

CRI/CSR CO2 combustion data are key metrics of coke quality and perf...

C25049Fusibility Of Coal Blends And Minerals In Coking

The CSIRO optical reflected light imaging CGA (Coal Grain Analysis) ...

C25045Stage Two - Assessment Of In Situ High-Temperature Strength Of Cokes

Stage I of this project established a reliable and repeatable proces...

Technical Market Support

Mine Site Greenhouse Gas Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

C27008Selective Absorption Of Methane By Ionic Liquids

The connection of a ventilation air methane (VAM) abatement plant di...

C24061Proof-Of-Concept Photocatalytic Destruction Of Methane For Coal Mining Fugitive Emissions Abatement

Australia's fugitive emissions in 2015 were 41 Mt CO2-e (representin...

C23052Novel Stone Dust Looping Process For Ventilation Air Methane Abatement - Phase 3

This multi‐phase project is concerned with the mitigation of m...

Mine Site Greenhouse Gas Mitigation

Low Emission Coal Use

Step-change technologies aimed at reducing greenhouse gas emissions.

Recently Completed Projects

C17060BGasification Of Australian Coals

Four Australian coals were trialled in the Siemens 5 MWth pilot scale ga...

C17060AOxyfuel Technology For Carbon Capture And Storage Critical Clean Coal Technology - Interim Support

The status of oxy-fuel technology for first-generation plant is indicate...

C18007Review Of Underground Coal Gasification

This report consists of a broad review of underground coal gasification,...

Low Emission Coal Use

Mining And The Community

The relationship between mines and the local community.

Recently Completed Projects

C16027Assessing Housing And Labour Market Impacts Of Mining Developments In Bowen Basin Communities

The focus of this ACARP-funded project has been to identify a number...

C22029Understanding And Managing Cumulative Impacts Of Coal Mining And Other Land Uses In Regions With Diversified Economies

The coal industry operates in the context of competing land-uses that sh...

C23016Approval And Planning Assessment Of Black Coal Mines In NSW And Qld: A Review Of Economic Assessment Techniques

This reports on issues surrounding economic assessment and analysis ...

Mining And The Community

NERDDC

National Energy Research,Development & Demonstration Council (NERDDC) reports - pre 1992.

Recently Completed Projects

1609-C1609Self Heating of Spoil Piles from Open Cut Coal Mines

Self Heating of Spoil Piles from Open Cut Coal Mines

1301-C1301Stress Control Methods for Optimised Development...

Stress Control Methods for Optimised Development and Extraction Operations

0033-C1356Commissioned Report: Australian Thermal Coals...

Commissioned Report: Australian Thermal Coals - An Industry Handbook

NERDDC