Coalbed gas formations are an important part of the world's natural gas resource. The energy industry classifies these formations as "unconventional gas reservoirs" and is continually looking for methods to economically develop them. Engineers use various methods of computer simulation to predict performance of coalbed gas formations. There is a tendency to use numerical simulation to predict their performance because of the complex production behavior of coalbed methane wells in the early life of a well. However, reservoir simulation may not be practical for situations in which individual wells need to be analyzed rapidly8 . One popular production analysis method is to analyze flowing production data using analytical techniques and type curve matching approaches. These analytical techniques are used to estimate reservoir properties from the matching of the historical data. In this study, public domain production data from producing U.S. coalbed methane basins has been used to illustrate analytical solutions and type curve matching for coalbed wells. The analyses include the use of analytical solutions for coalbed wells that take into account gas desorption from coal using isotherm data, analytical solutions for conventional gas reservoirs and Arp's decline curve analysis. It is assumed single gas phase, and that water production is minimal.

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