Natural gas production from coalbeds using horizontal wells may be of interest to producers in the future. Since sedimentary gas reserves are limited, the unconventional gas reservoirs could be an alternative resource to meet the demand for natural gas. Naturally fractured coalbeds with their dual porosity character can produce at much higher rates with horizontal wells. The presented paper shows an analytical solution for transient pressure response of a horizontal well in a coalbed reservoir. Effects of wellbore storage and skin on the solution are illustrated. The solution is developed for a semi-infinite, anisotropic coalbed reservoir assuming single phase gas flow. The solution can be used to generate type curves for particular reservoir geometry and subsequent determination of reservoir parameters.
The paper illustrates the application of type curve matching for a typical case through an example on computer generated data.