Research On High Gas Pressure Of Wu Group Coal Seam In Pingdingshan Mining Area

With a high production in coal mine,the coal and gas outburst occurred frequently,which has become a natural disaster greatly threatening underground coal mines and a serious threat to the lives of miners and and coal mine safety production.Coal seam gas pressure is a major determinant of content,it is the power source of the gas flow and one of the important energy source of coal and gas outburst,as one of the most important parameters of prevention and control of gas technology,the study of the coal seam gas pressure has certain importance and practical significance.Pingdingshan mining area has a complex geological structure,and the Wu group coal seam in this area is of high gas pressure(the highest gas pressure is 6.61MPa).In order to find out the reason of high coal seam gas pressure of Wu group coal seam in Pingdingshan mining area,started with the collected field data,combined with the geological structure features,measured gas parameters,characteristic of in-situ stress field,development law of tectonically deformed coal and the hydrogeological condition,this paper analyzed the gas occurrence feature,how the regional geological structure formation and evolution influenced the gas occurrence and emissions,the coal formation,metamorphism and the hydrocarbon generation of Wu group coal seam.And then,it focused on how the geological structure,stratum feature,the roof and floor lithologic of coal seam and the hydrodynamic conditions effected the gas pressure and content in Shoushan No.1 mine using the architectonical control of gas occurrence theory.For all the analysis,affected by the indo-chinese epoch,yanshan period and Himalayan period geologic activity,the structures of fold and fault in Pingdingshan mining area developed better.Controlled and influenced by regional tectonic movement,the gas occurrence,development and distribution of the tectonic coal,in-situ stress in this area have a great difference between east and west,but they all have a good consistency with the geological structure characteristics of the mining area.The formation and evolution of the structure in this area controled the coal seam gas generation and occurrence,emission,formed the general high gas pressure of Wu and Ji,it is also the main reason for the difference of gas content and pressure between east andwest;The unique three-dimensional enclosed structure caused by the structure features,the roof and floor of Wu group coal seam which constitute of mudstone and thick sandy mudstone,the weak hydrodynamic conditions and the high horizontal compression stress is the main reason that caused the high coal seam gas pressure of Wu group coal seam in Shoushan No.1 mine.