CHARACTERISTICS OF THE UPPER PALEOZOIC COAL RESERVOIR AND ITS GAS-BEARING POTENTIAL IN SHENMU, THE ORDOS BASIN

Studies of longitudinal and horizontal distribution of coal reservoir,macroscopic petrographic types,microcosmic petrographic component,pore configuration and permeability,vitrinite reflectance as well as absorbability in coal-bearing formation of Neopaleozoic in Shenmu area of the Ordos Basin indicate that,coal beds are thicker in the east and west,but thinner in the north and south.Coal bed thickness satisfies the demand of coal seam gas development.Most coal is semi-bright.Semi-dull coal distributes mainly in the eastern margin,characterized by low water cut,medium ash content and high vaporization.Vitrinite takes the first place in petrographic micro-petrological units,and the second is inertinite.Pores are mainly micropores and intermediate pores.Degree of coalification is ascending from north to south in the region of interest,showing low-medium degree entirely.Adsorptive capacity is relatively strong and coal seam gas is saturated,even oversaturated,displaying tremendously potential.Reservoir conditions are qualified for exploration and development of coal seam gas.