The main objective of this project is to simulate a model case to show characteristics of coal bed methane, while seeking the capabilities and limitations of ECLIPSE simulator. The classic methane production technology- depressurization of coal bed is studied here. The model is successfully simulated, however with the time constraint, simulation of second model with CO² injection was not achieved.A base case with four other parameters varying cases are simulated here. The result generated from the base case is satisfactory as it matches the basic coalbed methane theory, where gas produced with depressurization of the coal bed. There is a time lag before gas production and a long production life of methane shown in the result. This is due to the model specified and incapability of the ECLIPSE simulator, which will be further illustrated in the report.Further sensitivity study of the model is done by varying the coal bed permeability and matrixfracture diffusivity multipliers (DIFFMMF). Results are shown to follow the Fick's Law and Darcy's Law of diffusion in the coal matrix and rock fracture. Capability of ECLIPSE simulator in taking these changes into account is shown.Coalbed methane model is a new model in ECLIPSE 2000a. There is limitations and incapability of the simulator, which will be illustrated in the report. Errors from simulator are also discussed in the report.Further development of the coal bed methane model in the ECLIPSE simulator is needed. In the report, other potential for further development is discussed and possible further study of the topic is identified.