盐岩体储库裂缝流体渗流数值模拟

结合中国地下油气储库建造过程中所出现层状盐岩体问题，建立盐岩体裂缝流体渗流数学模型，并进行了相应的数值模拟。数值模拟结果表明，高压流体裂缝渗透过程中，沿裂缝通道上，流体压力在逐步降低。对于油气等稳定性流体，在裂缝渗流扩展的通道上，盐岩体裂缝呈扇形状张开；对于水溶液来讲，由于盐岩溶解的影响，靠近储库腔体壁附近的裂缝宽度较大，渗透率较高，在整个裂缝通道上，压力降低较慢，扩展距离也远于高压油气流体作用下的情况。结果提示：在盐岩体溶腔油气储库运营过程中，严格控制腔体压力不得大于地层应力及其抗拉强度；同时应控制天然气的采出速率，防止腔体内水合物的生成。以此来避免盐岩体在分层界面的水溶液渗透（流），保持腔体的致密性及稳定性。对中国在盐岩体中油气储库的建造及运行具有十分重要的意义和价值。

Mathematical model and numerical simulation of pressured fluids seepage in salt rock mass

According to the reality of bedded rock salt and clay interlayer in China,the constitutive model of seepage in rock salt mass is constituted and some numerical simulations are carried out in this paper.Results illustrate that the fluid pressure decreases along the infiltrated direction and the aperture of the opened fracture differ with the different infiltrated fluids,the aperture of the water-infiltrated and fan-shaped fracture is wider than those of the oil-or gas-infiltrated because of dissolvability of salt in the unsaturated brine,the pressure gradient is small and its infiltrated area is wide simultaneously.It can be concluded that the inner pressure of oil or gas repository should not be high up to the sum of the local ground stress and the tensile strengths of the interlayer,at the same time,the output speed of the pressured gas should be controlled to avoid the generation of hydrate in the cavity.Thus the tightness and stability of the oil and gas repository can be guaranteed.The study is significant and meaningful for construction and operation of oil and gas repository in bedded rock salt of China.