基于流固耦合的含夹层盐岩储库渗流研究

发布时间：2019-05-29 05:25

【摘要】：盐岩属于一种软岩,结构致密、渗透率和孔隙度极低,具有良好的蠕变和损伤自恢复能力。我国的盐岩有着软弱夹层多、单层厚度薄的特点,这与国外大而厚的盐丘相比有着很大的不同。含软弱夹层盐岩储气库的气体渗透机制十分复杂,含软弱夹层的渗流力学模型和数值计算方法是解决评估储气库气体渗透范围的关键。本文结合以往的研究成果分析流固耦合作用对储气库的影响,实现了渗透率的动态演化过程,得到了一些有价值的成果。(1)流固耦合作用,流体介质会扩大洞室周围的塑性区面积;同时流体介质的引入在不同的储库内压下对损伤变量的分布也产生不同的影响。(2)采用PWIPP与userc_d模型进行计算,其渗流的影响范围有着很大不同。由于损伤对渗透率、孔隙度的影响更大,所以userc_d模型计算得到的渗流影响范围比PWIPP模型要大。当前的相关研究中,学者们针对渗流问题中的渗透率和孔隙度大都设置为某一定值。本文实现了渗透率和孔隙度的动态演化,有两个创新点。(1)粘弹塑性含夹层盐岩储库渗流特性分析中,利用渗透率变化理论实现了渗透率和孔隙度的动态演化过程,并用单相液体稳态渗流理论验证了数值模拟计算的正确性。(2)考虑损伤的含夹层盐岩储库渗流特性分析中,利用损伤-渗透率关系试验实现了渗透率和孔隙度的动态演化过程。
[Abstract]:Salt rock belongs to a kind of soft rock, which has compact structure, very low permeability and porosity, and has good creep and damage self-recovery ability. The salt rocks in China have the characteristics of many weak interlayers and thin monolayer thickness, which is very different from the large and thick salt dunes abroad. The gas permeability mechanism of salt rock gas storage with weak interlayer is very complex. The seepage mechanics model and numerical calculation method with weak interlayer are the key to evaluate the gas permeability range of gas storage. In this paper, the influence of fluid-solid coupling on gas storage is analyzed based on the previous research results, the dynamic evolution process of permeability is realized, and some valuable results are obtained. (1) fluid-solid coupling, The fluid medium will expand the plastic zone area around the caverns. At the same time, the introduction of fluid media under different reservoir pressure also has different effects on the distribution of damage variables. (2) using PWIPP and userc_d model to calculate, the influence range of seepage is very different. Because the damage has a greater influence on permeability and porosity, the seepage influence range calculated by userc_d model is larger than that by PWIPP model. In the current related research, most of the scholars set the permeability and porosity to a certain value in the seepage problem. In this paper, the dynamic evolution of permeability and porosity is realized, and there are two innovations. (1) in the analysis of seepage characteristics of Viscoelastic-plastic interlayer salt reservoir, the dynamic evolution process of permeability and porosity is realized by using permeability change theory. The correctness of numerical simulation calculation is verified by single-phase liquid steady-state seepage theory. (2) in the analysis of seepage characteristics of interlayer salt reservoir considering damage, The dynamic evolution process of permeability and porosity is realized by damage-permeability relationship test.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE822

【共引文献】