Coalbed methane plays are unique when compared to conventional sedimentary reservoirs and also can vary greatly between the different locations and depths. Due to these characteristics, the drilling fluids must be tailored to each specific coal seam in a particular location in order to optimize the production capabilities and wellbore design. There are a series of ten analytical methods of analysis that will try to characterize critical aspects of the well program to design a fluid system for surface, intermediate hole and the drill-in fluid for the production zone. This systematic approach will initially target any previous drilling problems that have been observed in the area as well as the wellbore design to ensure that a cased well is drilled. It will then focus on designing a drill-in fluid to reduce formation damage and optimize productivity. A case study of a coalbed methane project from the Washakie Basin in Wyoming demonstrates the success of this method. The tailored coalbed methane fluid system reduced the previously experienced problems in the area such as mud rings and sloughing shales as well as reducing the overall drilling time. The fluid system was also designed to reduce the formation damage through a theoretical analysis of the chemistry and damage mechanisms. Productivity results have yet to be determined.

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