Study Of Gas Geology And Gas Forecast In Tiantai Coal Mine

Using gas geology research methods and taking Shouyang Tiantai mine8+9#coalseam as the research object, through the gas occurrence tectonic level control theory,thispaper has researched the tectonic evolution of Qinshui Basin and Yangquan miningarea,and researched the effect of coalification of the buried depth of coal seams, thethermal evolution and hydrocarbon generation for region and mining area structuralevolution, and then analysed the gas geology rule of Tiantai mine combined with avariety of geological tectonic characteristics and took the gas prediction.In Qinshui Basin, the Indosinian tectonic movement manifested the extrusion stressfield in the direction of SN and tectonic deformation is weak; In the early and middleperiod of Yanshan, the tectonic stress field showed sinistral compresso-shear nature, thedirection of main structure line rotated counterclockwise, changing from EW to NE andNNE gradually; from later period of Yanshan to Himalayan period, the tectonicmovement changed from extrusion system to tension system mainly because of theNW-SE strong tension action. In this tectonic stress background, many structurecombinations with different directions and natures were formed in the basin, whichcontrolled the coalbed gas enrichment in different effects.The Yangquan mining area is located in the edge of Qinshui coalfield northern andTaihang Mountain anticlinorium West wing, which’s structural characteristics andhistorical evolution are mainly controled by the Taihang Mountain orogenic belt, Fupinguplift and Qinshui large compound syncline basin tectonic evolution. Tiantai mine islocated in northern margin of Yangquan mining area Western, the main structure issouth monoclinic dumping and on which developed a series of secondary near EW foldsand faults. By collating and analysing the large amount of ventilation, gas andgeological datas since coal mine construction, this paper has researched the controlaction on gas for various structure in the minefield and the effect of gas occurrence forcoal thickness, buried depth of coal seam, karst collapse column, hydrological andgeological characteristics and so on. After a comprehensive analysis, we take the burieddepth of coal seam as the main control factors effect on gas occurrence of8+9#coalseam to predict the gas content and emission, divide gas weathered zone of the coal-bed, evaluate the outburst danger of8+9#coal seam and the outburst dangerous area waspreliminary classificated. Finally, the8+9#coal-bed gas resources amount werecalculated by volume method on partition.