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Conference Paper

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This conference paper was originally published as Ashelford, D, Longwall "Pore Pressure" Gas Emission Model, in Aziz, N (ed), Coal 2003: Coal Operators' Conference, University of Wollongong & the Australasian Institute of Mining and Metallurgy, 2003, 21-29.


Extraction of coal by longwall mining methods has improved greatly over recent years with tonnage rates per week now surpassing yearly tonnes of a few years ago. As mines go deeper and tonnage rates increase then gas emission also increases. For the purposes of understanding gas emission and planning strategies short and long term, modelling of gas emission using the “Pore Pressure” longwall gas emission technique, illustrated is an attempt to model this phenomenon. The input data to the model includes the gas reservoir properties relevant to underground coal seams and extraction of coal using the longwall technique to evaluate the release of gas into the mine workings. Variations in weekly production, face airflow quantities, the efficiency of gas drainage levels and differing face widths can be tested using the model. Mine planners can use the interactive spreadsheet developed through this model to assess the limits of production, ventilation capacity and gas drainage requirements.

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