岩石热增渗机理初探

DISCUSSION OF THE PERMEABILITY INCREASING MECHANISM OF THERMAL TREATED ROCK

在大气压力下 ,对取自储层的大量岩心在 10 0～ 80 0℃范围内进行加热处理 ,测量其渗透率和孔隙度随温度的变化关系。实验结果表明 ,热处理过程中岩石渗透率和孔隙度等物理性质存在一个突变温度域 ;经过高温处理后的岩石 ,其渗透率和孔隙度随温度升高而增加 ;温度达到 80 0℃时渗透率可增大 2个数量级 ,孔隙度可提高数倍。根据这些实验结果 ,从岩石孔隙结构特点、岩石矿物脱水破坏、热应力集中、化学键断裂、应力松弛等理论出发 ,对岩石热增渗机理进行了初步的探讨和分析。

An experimental study of high temperature treatment was carried out on a lot of rock samples, which come from reservoir formation, to determine the effect of thermal treatment on permeability and porosity, which were measured under the atmospheric pressure and room temperature. Results indicated that the changes of permeability and porosity exist a threshold temperature and they increased with increasing temperature in the rang of 100℃ to 800℃. Up to 800℃, permeability increased two orders and porosity increased ten times. According to these experiment results, the permeability increasing mechanism of thermal treated rock was discussed and analyzed in this paper from the theories of pore structure characteristic?mineral dehydration and destruction? thermal stress concentration?chemical bond breakage?stress relaxation and so on.