盐岩的渗透特性研究

针对盐岩的低渗透特性,提出了在渗透率低于10-22m2和高于10-22m2两种情况所采用的计算理论,即可以利用岩石扩散与对流-扩散理论和达西理论来研究其渗透特性,并给出了试验室测试盐岩渗透率的计算公式。通过盐岩的渗透试验:①研究了损伤对盐岩渗透率的影响,并指出当盐岩所处的应力状态没有超出盐岩的损伤临界值时,盐岩的渗透率基本保持其原始渗透率,当盐岩发生损伤后,其渗透率明显增加;②同时也研究了围压对盐岩渗透率的影响。结果表明,在其它条件相同的情况下,作用在盐岩上的围压越高,盐岩的渗透率越低,并给出了围压与渗透率的拟合关系式。

Investigations on permeability of rock salt

Calculation theories used for lower permeability of rock salt were presented to two cases of permeability ①K<10-22 m2 and ② K>10-22 m2, that is to say, the diffusion and convective-diffusion theory and Darcy law could be used to investigate permeability behaviors of rock salt, and the formulations of the permeability for experiments in the laboratory were given. According to the experiments, the influences of the damage of rock salt on the permeability were investigated, and the results show that the permeability has hardly changed compared with permeability of natural rock salt when the stress on the rock salt is less than the stress in dilatancy criteria and there is no damage for rock salt; otherwise, the permeability will be increased rapidly. On the other hand, confining pressure makes a great impact on the permeability; and the results indicate that the permeability will decrease as the confining pressure increases under the same other conditions; in the meanwhile, experiential formulation with confining pressure taken into consideration is presented.