Cause Analysis and Logging Comprehensive Evaluation of Low Production of Coalbed Methane Wells in Baode Area

To fully tap the remaining resources of coalbed methane (CBM), this study conducts a detailed evaluation of the residual potential of CBM old wells. Taking the Baode block as the research area, we carry out an analysis of the causes of low productivity in old wells and a logging re-examination study.‌ Faced with the current development status characterized by a high proportion of old wells, rapid decline in productivity, and low wellhead pressure, we comprehensively apply data from logging, fracturing, gas testing, pilot production, and production dynamics. We summarize the causes of low productivity in the block and simultaneously construct a potential evaluation method for old wells in the study area, establishing key indicators such as "logging parameters, reservoir parameters, structural parameters, engineering parameters, and predicted production.“‌‌ Ultimately, we submit the potential intervals, potential levels, and exploitation plans for the potential wells. Through application in the research block, the results show that the average daily increase in production per well after implementation exceeds 1050 cubic meters, and the average additional production per well exceeds 3 million cubic meters. The application effect is significant, providing positive guidance for understanding the causes of low productivity in old wells and for increasing reserves and tapping potential.