Quantitative evaluation of reservoir heterogeneity of coal seam by using logging data

Aiming at the big influence of heterogeneity on CBM extraction, through analyzing the permeability distribution law by using logging data, the planar and vertical heterogeneous degree of coal seam can be evaluated quantitatively. Darcy formula was used to determine the permeability of coal matrix, dual lateral logging data were used to estimate the permeability of fissures, the cumulative distribution curve corresponding to the contribution rate of seam permeability under the ordinal percentage coordinate was drawn, the slope of the cumulative distribution curve after transformation of definition coordinate is the coefficient of heyerogeneous degree. The actual application shows the coefficient of heterogeneous degree can reflect the horizontal and vertical difference of the phsical properties of coal seam, and then the hetrogeneity of seam can be evaluated quantitatively.