Abstract

Geophysical Well logs are important information source for CBM prospect evaluation. It identifies coal layers without any ambiguity and offers a permanent record, which facilitates spatial correlation, and work out geological history of the area by workers of different discipline at the same time or at different point of time. Geophysical well log characteristics of coal beds bears a strong semblance to coal ranking, recognizes cleat potential & fracture zones and provides inferences on thermal history, pressure regime and about stress field of the area that are vital for prospect evaluation.

Well logs are most reliable data source in various map preparation needed for reserve estimation, forecast production potential and plan for optimal recovery of methane gas. Well log data being a permanent record, offers a strong foundation for generating transforms between laboratories derived data vis-à-vis log data for continuous evaluation and apply corrective reality measures to incorporate subtle local variations caused due to geologic environmental changes.

These transforms have found wider acceptance throughout the globe for various assessment, and handy, to make forecast on production potential. Among the array of logs used in CBM prospect evaluation, density log occupies a special position. This is because of its wider use e.g. in various assessments, framing transforms, and Gas In Place (GIP) calculation through volumetric method.