Geological Characteristics Of Coalbed Methane And Selective Targets In Guizhou Bide Block

Coalbed methane,also called coalbed “wasi”,is a kind of unconventional natural gas stored in the coalbed and adjacent rock formations.This article takes the Liupanshui area Bide block in the west of Guizhou as the research object.Based on a large number of drilling data and measured data,the effect of coalbed thickness,depth,coal and rock structure and physical properties on coalbed gas enrichment is analyzed.Research shows:The coalbed transverse distribution in this block is more stable,but the thickness of single layer varies greatly.the number of layers in vertical is many,and the single layer is thin.The types of coal rock in this area are mainly semi-bright coal and semi-dark coal,the vitrinite content is high,a small amount of inertinite,mainly of cataclastic structure and primary structure,high degree of coal and rock thermal evolution,low porosity and low permeability.Based on the study of coal bearing strata and characteristics of coal rock,the gas content ability of coal rock is emphatically analyzed.The relation between gas content and other factors is also analyzed.So,the gas content,permeability,coal and rock structure is the main controlling factor of CBM enrichment.Finally,the selective principle of the study area is established,and the favorable area is delineated preliminarily.