Predicting Water Production Volumes and Timetables Using Critical Desorption Data

Mones, Charles¹ (1) WellDog, Inc, Laramie, WY

It is necessary to use critical desorption pressure (CDP) in conjunction with the Langmuir isotherm to predict the performance of an under saturated coalbed reservoir, such as in the Powder River basin. For water saturated reservoirs, the difference between the reservoir pressure and CDP indicate the pressure reduction needed to initiate the release of methane. For water saturated reservoirs, this pressure reduction is accomplished by producing water. This paper presents the effect of CDP on the quantity of water that must be produced from a coalbed reservoir to establish methane production.