Coalbed methane reservoir dynamic prediction model by combination of material balance equation and crossflow-diffusion

ABSTRACT

The proposed dynamic prediction model is based on the occurrence and migration law of coalbed methane and on the pseudo-steady state diffusion model. The model integrated multi-phase flow theory and material balance equation. It is established by considering not only desorption and diffusion but also crossflow. Moreover, the calculation results show the rationality of the method used. The research analyzes the effects of crossflow factor and diffusion coefficient on development effectiveness. The effect of crossflow factor is obvious in the late production stage but not in the early stage. The diffusion coefficient affects gas production during the exploitation stage.

KEYWORDS:

• Crossflow
• diffusion
• dual media
• dynamic prediction
• material balance equation

Additional information

Funding

This research is supported by the Fundamental Research Funds of the Central Universities, the National Special Fund (No. 2011ZX05009-006), and the National Basic Research Program of China (No. 2009CB219600).