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在中等温度(25℃~90℃)和渗透压的条件下,裂隙渗透性对矿物质的溶解表现的很敏感。因此重点通过4个温度平台阶段(25℃,50℃,70℃,90℃),以温变对流量和等效水力开度的调节过程来反映温度对石灰岩裂隙渗透特性演化规律的影响。测量反应过程中岩样的渗透流量和渗出液的离子浓度,并将测量的渗流量经过经典的立方定律变换得到裂隙开度随时间的变化情况。实验结果表明:升温过程中流量和等效水力开度表现出明显增大的趋势,恒温过程中等效水力开度逐渐变小并趋于稳定;在不变的有效应力下,经历渗透压增大后,随着温度的升高,裂隙开度总体呈下降趋势。通过分析渗流量、等效水力开度和矿物离子浓度随时间变化的过程,以及它们之间的内部关系,得出温度升高能促进应力作用和渗流作用,渗流通道的局部溶解作用也随着温度的变化而改变,从而影响压力溶解和自由溶解的进程。
Fracture permeability is sensitive to the dissolution behavior of minerals at moderate temperatures (25 ° C to 90 ° C) and attrition pressures. Therefore, the influence of temperature on the law of permeability evolution of limestone fractures is mainly reflected in the adjustment process of temperature-dependent convection and equivalent hydraulic opening through four temperature platform stages (25 ℃, 50 ℃, 70 ℃, 90 ℃). The permeability of rock sample and the ion concentration of exudate during the reaction were measured. The measured seepage volume was transformed by the classical cubic law to get the variation of the crack opening with time. The experimental results show that the flow rate and equivalent hydraulic opening increase obviously during the heating process, and the equivalent hydraulic opening gradually becomes smaller and tends to be stable during the constant temperature. Under the constant effective stress, the osmotic pressure increases After that, as the temperature increased, the crack opening generally showed a downward trend. By analyzing the process of seepage, equivalent hydraulic opening and mineral ion concentration with time, as well as the internal relationship between them, it is concluded that the increase of temperature can promote the stress and seepage. The local dissolution of seepage channel also changes with temperature Changes in the change, thus affecting the process of pressure dissolution and free dissolution.