Application of material balance method to deliverability prediction of closed coal-bed methane reservoir

The study of the production dynamics for coal-bed methane reservoir is very valuable for it differs from normal gas reservoir in its specific manner of storage and the mechanics of flow through porous media, and multiphase flow in the earlier stage of production makes it more complicated.In this paper, the history production data were firstly analyzed by history matching, and the future production dynamics were predicted based on these matched parameters.By comparisons of the predicted average pressure, water saturation and rates of gas and water with simulated values by CMG, it's reliable to predict the production dynamics of CBM reservoir by the proposed method, especially after the peak of gas production.The limits of material balance method and their influences are also analyzed when applied for this forecast.