A new and robust approach was developed to simulate flow of methane gas in coalbed methane reservoirs. The proposed simulation model was developed for a 2-phase, 3-dimension, single porosity with desorption/adsorption phenomena. The model was developed based on mass balance concept and control volume approach. Flow of gas in the fracture is modeled by Darcy's Law, while movement of gas in the coal matrix is assumed to obey diffusive process. A new equilibrium equation is proposed to represent the process. To verify the developed model, we history matched Well # 1, an active gas well over a period of about 4 years. The well was producing from Fruitland formation in San Juan Basin, northwest of New Mexico. In addition, we also made prediction study of Well # 1 in which we investigated the effect of completion techniques (vertical vs. horizontal), fracture and stress sensitive permeability on the overall performance of Well # 1. The results of the study indicate that the developed model is able to predict the performance of a coalbed methane reservoir quite well. The model behaves as predicted and it closely matches the past performance of Well #1. The results also highlight the importance of stress sensitive permeability consideration in coalbed methane evaluation even in low fairway area of San Juan Basin where permeability is less than 1.0 md. Neglecting the effect may result in overestimation of reservoir performance. The study also suggests that fracturing job might be a crucial element to prevent Well # 1 from being shut down prematurely.

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