The application of well logs in the CBM industry is usually limited to the identification of coal seams, coal thickness calculation, and estimation of gas in place1 . In order to take full advantage of the abundant well log data collected at the Drunkards Wash Unit (DWU) and better understand log responses in CBM reservoirs, a study was performed with three major objectives. First, a new method was devised to calculate a permeability indicator using the shallow resistivity measured by the focused electrode tool. Second, the resistivity log was observed as a critical parameter to distinguish coal from non-coal formations in significantly enlarged well bores. And finally, based on the observed correlations between coal and log parameters, a comprehensive log cutoff system was established and a computer analysis model was developed to identify a diverse coal lithology system present at DWU.

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