National University of Mining and Technology MISIS, Moscow, Russia:

E. A. Egorova, Leading Engineer
K. S. Kolikov, Professor, Doctor of Engineering Sciences, +7(916)400-85-19

Egyptian Engineering Group, Cairo, Egypt:
H. A. Meguid, Chief Executive Officer

The use of different technologies and machinery with high productivity for coal mining as well as the work under the system “mine–longwall face” results in reduction of reserve capacity and, accordingly, demands high security measurement. This problem can be solved by the analysis of stress–strain conditions in a coal seam, which is responsible for the emission from abnormal zones. Such zones are related with both gas-dynamic events and emission into mine workings. One of the main conditions for the prediction of zones with abnormal gas content and gas emission is geological modeling of mining fields. The article presents the results of stress–strain modeling for coal seam at the presence of lenses of competent rocks, which act as stress raisers. The distance of influence between coal seam and lenses is estimated, as well as the influence of deformation characteristics of the lenses on the variation of the relative permeability of the coal seam is assessed. It is demonstrated that the presence of lenses in the roof and bottom results in the expansion of lower permeability area and induces a slight increase in the permeability at the edges. Inclusion of heterogeneity of geological structure and host rocks as well as nonuniformity of their physical and mechanical properties allows predicting presence of zones with abnormal gas permeability along coal seams. This approach can be recommended for identification of coal seam zones suitable for methane capturing.
The study has been supported by the Ministry of Education of the Russian Federation in the framework of state assignment for MISI under Agreement No. 15.575.21 0025. Unique Identification Number RFMEFI57514X0025.

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