CBM Well Structure Analysis from Ultrasonic Image Logs

Coalbed methane is enriched in Shanxi Province, China, but the geological structure of coalbed methane reservoir is complex. At the present time, there are some direct or indirect methods which can be used to identify the reservoir structure information. However, ultrasonic imaging logging is only suitable for a few CBM well research programs in China, because it is restricted by acquisition costs and measurement environments. The ultrasonic imaging logging of CBM Well XJ-6 was used to analyze the ultrasonic logging response characteristics of structure of this well, as well as to explain and obtain quantitative information regarding the fractures and breakout zones. The results showed that the fracture and breakout zone patterns of the coal-seam formation were similar in the Upper Shihezi Formation, Lower Shihezi Formation, and Shanxi Formation.. This study's results can be potentially used for the effective recognition of coalbed methane, as well as for future explorations and developments in this field.