Abstract

The eastern part of the Bokaro coalbed methane reservoir shows heterogeneity and complexity in geological formation during drilling wells. The geological surprises include the observation of very low resistivity formation, missing coal seam, thickness variation of coal, carbon dioxide (CO2) generation during production, and comparative variation of gas content in the seam. Several maps were generated based on the well log analysis from 91 wells in the study area. The path of a very low resistive signature shows an NW-SE trend which is observed below the Kargali Top seam and this affects the coal quality. Interestingly, the fault lines could easily be identified from the number of five objective coal seam and cumulative thickness contour map. During the production stage, it was observed that CO2 gas is also produced along with methane gas, and therefore data was compiled to map CO2 percentage. A methodology was applied to determine the seam-wise gas content based on the obtained regression equation from density and gamma ray log data with proximate analysis of the core sample, available in a few wells. Gas content using Kim