超临界CO2在低渗透煤层中渗流规律的实验研究

利用自主研发的THM三场耦合渗流实验系统,进行不同孔隙压力和温度条件下的超临界CO2在低渗透煤层中的渗流实验,得出不同温度下流速和压力梯度之间的关系,从而得到了低渗透煤层注入超临界CO2的非达西渗流规律,即流速与压力梯度变化规律呈现正指数关系.随着压力梯度的增大,渗透系数也不断的增大,且呈现正指数关系；在同一体积应力和压力梯度的条件下,温度越高,流速越快；温度在临界点附近,流速和渗透系数增加很快.

Experimental Study of Supercritical Carbon Dioxide Seepage Flow in Low Permeability Coal Seam

A series of seepage experiments of supercritical CO₂ were carried out under different conditions of pore pressure and temperature based on a self-developed THM three field coupled seepage experiment system. Relationship among the flow velocity and the pressure gradient at different temperatures were obtained. That is non-Darcy seepage regulation of supercritical CO₂ in low permeability seam, which means a positive exponential relation between the flow velocity and pressure gradient. The permeability coefficient increases along with the pressure gradient increase, and presents a positive exponential relationship; under the same volume stress and pressure gradient conditions, the higher the temperature is, the faster the flow velocity; when temperature approaches the critical point, the flow velocity and the permeability coefficient increase faster.