回灌溶液温度对咸水层渗透性能的影响

The effect of injected temperature on brine aquifer permeability

中文关键词: 咸水层储能  渗透性能  回灌温度

英文关键词: brine aquifer energy storage, permeability, injected temperature

中文摘要:

      作为清洁环保的供暖和制冷方式，季节性含水层储能与热泵技术相耦合，具有很好的经济效益和环境效益。然而，当咸水储层作为储能介质时，由于回灌溶液盐度和温度的变化会导致咸水层中粘土颗粒的释放、运移和沉积，引起孔隙通道的堵塞，造成储层的渗透性能降低。通过室内一维砂柱实验，对含有蒙脱石矿物成分的砂样，在不同回灌水头下采用不同温度的地下原水回灌时，溶液在砂样内的渗透系数变化进行了实验测试，分析了回灌温度对含水层渗透性能的影响。结果显示，随着回灌温度升高，溶液在砂样内的渗透系数减小；回灌溶液温度越高，渗透系数下降程度越大，当回灌水头为0.1 m时，回灌溶液温度由5 ℃升高至80 ℃，渗透系数下降了14 %；在回灌温度一定的情况下，回灌水头差越大，渗透系数下降的幅度越大，当回灌水头为0.2 m和0.48 m时，溶液在砂样中的渗透系数分别下降了16 %和18.2 %。通过定量地分析流体在储层内的渗透系数与回灌温度的变化规律，得到了不同回灌水头下，溶液渗透系数与回灌温度间的函数关系。

英文摘要:

      Seasonal aquifer energy storage combined with heat pump technology, as a clean and environmentally heating and cooling mode, has a great economic efficiency. However, when the brine aquifer is used as the energy storage medium, changes of injected fluid salinity and temperature can cause releasing, migration and deposition of clay particles in brine aquifer reservoir, and then result in the blockage of pore throats and reduction of aquifer permeability, due to the presence of clay minerals in brine aqueous medium. The permeability variations of seepage solution in the sand containing Montmorillonite minerals in different temperatures of injected solutions under different water head were studied through an indoor one-dimensional sand column experiment. Results indicate that the permeability coefficient reduce when in-creasing temperature, higher the solution temperature is, faster the permeability reduces. Under the water head difference of 0.1 m, when the temperature of injected solution increased 5 ℃ to 80 ℃, the permea-bility coefficient reduced by 14 %. Also, there is much permeability reduction with the water head differ-ence increasing when the injected solution temperature is certain. When the water head difference were 0.2 m and 0.48 m, the permeability of seepage solution in the sand decreased 16 % and 18.2 % respectively. According to quantitatively analyzing the variation of fluid permeability and injected solution temperature, the functional relationship between fluid permeability coefficient and injected solution temperature under different water heads is obtained.