本项目紧密围绕我国盐穴储气库低品位薄互层盐岩顶板封闭性机制这一关键科学问题，依托江苏淮安盐穴储气库工程，开展试验和理论研究。主要研究内容为：针对典型薄互层盐岩顶板中高杂质盐岩层，开展储库运行时各种应力状态下的气固耦合的室内模拟试验研究，探明盐岩的渗透演化规律及发生渗漏的条件，建立相应的渗透模型及扩容准则；针对薄互层盐岩顶板中的盐岩-泥岩交界面，开展力学及渗透耦合试验，辅以细观观察及切片技术，揭示交界面局部破损的演化特征，建立交界面破坏控制判据及渗漏局部通道形成的判定条件；最后，结合数值模拟及现场测试对相关模型及判据进行检验和修正，形成储气库低品位薄互层盐岩顶板封闭性能评价的理论和方法。研究成果可为我国盐穴储气库的地层选段、顶板设计及封闭性评价等提供重要依据。

This project aims at the key scientific issue in the sealability mechanism and assessment of the low grade thin interbedded salt rock cavern roof, to conduct experimental and theoretical study by depending on the demonstration projects of Huai’an underground salt gas storages. The main investigative contents includes: as for the high impure salt rock in roof strata, the stress-percolation coupling tests are to be conducted under variable stress regime, then the permeability evolution law and the onset condition of leakage are to be indicated and the corresponding percolation model and dilatancy-criterion are to be established. As for the different types of interfaces which connect the mudstone interlayer and salt rock layer, mechanical testing as well as permeability coupling testing is to be carried out. Micro-survey and observation of thin slices will be supplemented to investigate the fracture features of the interface. And then the control criteria of fracture and the decision condition of local percolation channels formation around the interface are to be proposed, respectively. In the end, the percolation model, control criteria as well as decision condition are to be verified and improved by comparing with the field measurements, and then the theory and method on evaluating the sealability of the low grade thin interbedded salt rock roof are to be formed. The results of this project can provide significant references for geological strata selection, roof designing and tightness assessment of the salt cavern in domestic.