Coal Reservoir Characteristics And CBM Development Unit Division In Southern Liulin Coal Mine Area

The division of CBM development unit is the basis of the coordinated development of coal and CBM.This paper takes the southern Liulin mining area as example,geological analysis and test were used,the geometric characteristics,coal structure,gas bearing,porosity and permeability,reservoir pressure,crustal stress,reservoir mechanical properties and water content evaluation of coal reservoirare deeply analyzed.The division index and principle of coalbed methane development unit are put forward,and the coal and coalbed methane coordinated development unit is further divided in the coal mine ofoptimal area,and the development model is established,which can provide theoretical guidance for the later development of coalbed methane.The final research results show: The coal seam is monoclinic in the study area,the coal seams with stable development and large thickness are coal seams No.4 and No.8;Simple structure in the study area,only in the northern part of the region developmnet Jucaita Cellar;The buried depth of the coal seam gradually increases from east to west.in the study area,the gas content shows the same trend,the critical saturation depth is approximately 1200 m,but the overall gas saturation is low,reservoir pressure state is undervoltage;The coal structure is mainly cataclastic coal,fragment-myrmyite coal only exists in the western part of No.4 coal seam;The permeability of Shaqu coal reservoir is better,followed by Hexi Mine,Shuangliu Mine is the worst,permeability increases with the increase of buried depth as a trend of decreasing power index;The water-rich grade of coal-bearing strata is weaker-relatively water-repellent,the type of rock seepage is micro-permeable – impervious,and the hydrodynamic conditions are weak;The depth of 600~800m is the preferred area for coal reservoir reconstruction.On the basis of the above research results,the principle of division of development units is proposed by the method of mathematical proportional thinking combined with the method of analytic hierarchy process.finally divided into ? class,? class advantage area,? disadvantage areabased on coal thickness,buried depth of coal seam,coal body structure,air content,crustal stress,layer spacing influence factors.The I class are mainly distributed in the Shaqu mine,the south of Shuangliu mine,the southern Hexi mine and the western part of the study area;The III class are mainly distributed in the eastern and western parts of the study area.Coal and coalbed methane coordinated development units classification and pattern configuration are taken in Shaqu coal mine of the advantage area ?.