地球物理场中的煤层瓦斯渗流方程

SEEPAGE EQUATION OF COALBED GAS IN GEOPHYSICAL FIELD

根据煤层瓦斯在地应力场、地温场和地电场中的渗流特性,确定了在地球物理场中的煤层瓦斯渗透率k(σT,E);该渗透率与有效应力σ成负指数关系、与温度T成幂函数关系、与电场强度E成正比关系。在此基础上,通过建立煤层瓦斯运动方程、连续性方程、气体状态方程和含量方程,推导得到了地球物理场中煤层瓦斯渗流方程。该煤层瓦斯渗流方程反映了地应力场、地温场和地电场对煤层瓦斯渗流的共同影响:作为一种新理论,在一定条件下,该渗流方程将是地球物理场作用下煤层瓦斯运移规律分析的理论基础。

According to the seepage properties of coalbed gas affected by in-situ stress field, geothermal temperature field and geoelectric field, the coal-bed gas permeability κ(σ, T, E) is investigated and obtained in geophysical field. The results indicate that coalbed gas permeability is related to the effect stress σ with a negative index, to the geothermal temperature T with a power function and proportional to the geoelectric field strength E. By establishing coalbed gas flow equation, coalbed gas flow continuity equation, coalbed state equation and coalbed gas content, the coalbed gas seepage equation is gotten in geophysical field. The coalbed gas seepage equation contains common influence of in-situ stress field, geothermal temperature field and geoelectric field on coalbed gas seepage properties. As a new theory, the coalbed gas seepage equation will be as a theoretic basis to discuss coalbed gas flow law in geophysical field under certain conditions.