温度和有效应力对砂岩孔隙度的影响

Test study concerning the effect of temperature and effective stress on porosity of sandstone

为探讨温度和有效应力对孔隙度的影响,在不同温度水平和不同有效应力水平下进行了砂岩的孔隙度试验,根据试验结果分析了温度和有效应力对砂岩孔隙度的影响。试验结果表明,在温度水平一定的条件下,砂岩的孔隙度随有效应力的增加而呈负指数规律减小;而在有效应力水平一定的条件下,温度对砂岩孔隙度的影响却很小。因此,当温度变化范围不大时,在工程实践中基本上可忽略温度变化对砂岩孔隙度的影响,从而近似认为岩石(体)的孔隙度只受有效应力的影响。

In order to study the effect of temperature and effective stress on porosity, the porosity tests for sandstone were conducted at various temperature levels and various effective pressure levels. Based on the test results, the effect of temperature and effective stress on porosity of sandstone are analyzed. The test results show that the porosity of sandstone decrease with the increasing effective stress at the fixed temperature level, following the law of negative exponent. However, at the fixed effective pressure level, the effect of temperature on the porosity of sandstone is very small. So, in the engineering practice, when the variation range of temperature is not great, it is proper to take no account of the effect of temperature on the porosity of sandstone on the whole, and the porosity is only affected by effective stress.