Gas Occurrence Characteristics And Gathering Regularity Of Deep Part Mine In Southwest Tangshan Mine

For the current situation of mining depth increasing and lacking of research inSouthwest Tangshan Mine, gathering the basic geologic information and gas data instudy area and other region of Tangshan Mine and defined the boundary of deep areaand shallow part after analyzing the gas characteristics of mined area reasonably.Based on the definition, the difference of gas geological conditions between deep areaand the shallow are compared using testing the coal and rock samples collected fromthe two area. Analysed the geological affecting factors of gas occurrence combinedthe gas emission and gas content characteristics and analysed the main controllinggeological factors of the deep area and the shallow part also. At last established theprediction model of gas content using multiple linear regression which based onnumeralization of deep and shallow geological factors. Finally, analysed the gasoccurrence characteristics and gathering regularity of study area.The research indicates that the structure of study area is complex and gasemission and gas content here are different hugely and both of the gas emission andgas content of coal seam9are the highest. The characteristic of gas emission presentsgreat difference in the over and under-750m, and consequently, taking the depth-750m as the boundary of deep area and shallow in this thesis. The result ofcomparing gas geology conditions in deep and shallow area shows that the deep parthave more micropore and stronger ability of gas adsorption. And also the temperaturein the deep area is higher than the shallow while the geothermal gradient in shallow ishigher. Ground stress testing indicates that the stress in deep area is vertical stressmainly while in shallow part is horizontal stress and the change depth ranges from-800m to1000m. Analysis shows that the difference of gas emission in deep andshallow part is mainly caused by the change of ground stress in the two part.The research of gas occurrence’s affecting factors shows that structuralenvironment, buried depth, hydrogeological condition, wall rock characteristics,formation temperature and crustal stress condition are all affect the gas occurrence.And the gas in deep part mainly controlled by buried depth, structural environment,wall rock characteristics and crustal stress condition while formation temperature,structural conditions and roof clay rate are the main controlling factors in shallow.The result of gas content prediction indicates that coal seam9has the highest gascontent with an average value of4.5m3/t. The gas content in both side of study area and the southern boundary is higher and the gas content of deep part higher than theshallow in the mass. The difference of gas content in deep part smaller than that inshallow and there has the phenomenon of gas content uprush in shallow part.