Study On Geological Characteristics Of Minable Coal Seam In PB Area In Southeastern Ordos Basin

In order to strengthen the fine geological study of coal exploration in PB area,this paper collects the drilling and geological data and well logging data in the area on the basis of a large number of literature investigation.Firstly,stratigraphic division and correlation were carried out to establish an accurate stratigraphic correlation framework.Secondly,the characteristics of coal seam logging response are studied and the typical lithology logging identification chart is established.Thirdly,the comprehensive interpretation method of recoverable coal seams was studied,and the industrial composition modeling of coal seams was carried out based on the test and analysis data in the study area to reveal the plane distribution characteristics of industrial composition of coal seams in the study area.Then,the interpretation method of mechanical parameters of mining coal seam is studied to reveal the rock mechanical characteristics of coal seam roof and floor.Finally,the distribution characteristics of mining coal seam are evaluated.The results show that the microstructural characteristics of the top of 4#,5# and 11# coal in the PB area are higher in the east and lower gradually in the west,and the microstructural characteristics show certain similarity and inheritance.The combination of natural gamma ray,density logging,acoustic logging,resistivity logging and other curves can effectively distinguish and identify coal lithology.The coal body structure of 4#,5# and 11# coal is mainly pulverized coal.The ash content of 4#,5# and 11# coals is complementary to the fixed carbon content,while the volatile and moisture content are similar to the ash content.The floor rock of 4# coal seam is hard rock,the floor rock of 5# coal seam is soft rock,and the floor rock of 11# coal seam is hard rock.The average thickness of 4# coal seam is 1.54 m,it is basically minable in the whole area and belongs to a relatively stable medium thick coal seam.The average thickness of 5# coal seam is 3.60 m,it can be mined in the whole area,and is a relatively stable medium and thick coal seam.The average thickness of 11# coal seam is1.76 m,which belongs to a relatively stable medium thick coal seam.The coal seams in mining area are divided into three types by grey correlation analysis method.