- 期刊
- OpenAccess
Prediction of Coalbed Methane Well Production by Analytical Method
並列摘要
The motive of the study is to propose a water-gas two-phase flow model to depict the characteristics of Coalbed Methane (CBM) transporting in the unsaturated coalbed and predict the production of CBM well. The proposed model is established based on Buckley-Leverett equation. The calculating equations of daily gas and water production of CBM well are derived from the proposed model. A program is achieved based on the equations and an actual CBM well is simulated as an example. The simulated results are verified by the actual site monitoring values. Moreover, the effects of permeability, porosity, well control radius, coalbed thickness and coal-rock matrix radius on the daily gas production and cumulative gas production of CBM well are studied. The comprehensive results address that the equations of daily gas production and cumulative gas production are good agreement with the monitoring values. Daily gas production increases with increasing permeability. Greater porosity means higher initial and stable daily gas production. Appropriate increase of the well control radius can improve the initial and stable daily gas production. However, when the well control radius reaches a critical value, it has no effect on the daily gas production. The initial gas production increases greatly with increasing coalbed thickness and matrix radius.