深部盐穴储气库密闭性评价基础研究

This project aims at the key scientific issues in theories and methods of sealability assessment of the bedded salt rock gas-storages to conduct fundamental application research,such as demonstration projects of gas storages in Jiangsu Jintan, Hubei Huangchang and He'nan Pingdingshan and so on.Main research contents are as follows: Firstly,for the typical different sedimentary rhythm interfaces,coupling states of permeability tests and simultaneous nonedestructive measurements will be conducted,then the evolution regulation of damage-permeability for different interface types, as well as the permeability mutation-disaster formation criteria will be investigated. Secondly, for the salt rock with different structure-matrix and components from different mines,the permeability tests and meso-scale research under the realistic cavern running conditions will be conducted, and in turn the internal mechanism of dilatancy and its induced threshold of permeability-increasing to disater formation conditions of percolation will be indicated. Then the analysis model of rock wall dilatancy and permeability increasing regions of the gas storages can be established.Thirdly,for the nonsaline cap rock and interlayers,meso-indexes and macro-indexes of sealability will systematically be carried out, and then the sealability mechanism of the cap rock and interlayer, as well as the main-controlling indexes of sealability of caverns can be revealed respectively. In the end, by comparing the results of field measurements of the equiavalent demonstration projects,field applications and modifications of the proposed analysis model of the sealability, as well as the criteria of threshold of disasters can be made.This project can provide importantly fundamental theories and methods for the establishment of comprehensive sealability assessment system of the deep underground gas storages in bedded salt formations, and can also supply relative theoritical and references for disaster avoidance in phases of site selection,cavern desighning and running periods respectively.

本项目紧紧围绕我国层状盐岩地下储气库（盐穴储气库）密闭性评价，以我国江苏金坛、湖北黄场、河南平顶山等在建的地下盐穴储气库为示范工程，开展应用基础研究。主要内容包括：对不同沉积韵律特征的典型界面开展多场耦合条件下的渗透试验和同步无损检测，揭示不同类型界面的破损-渗透演化规律并建立渗透突变的临界判据；对不同组构特性盐岩开展储库各种运行工况下的渗透耦合及细观演化试验，探明盐岩扩容发展及诱发渗透突变的内在机制，进而建立储库围岩扩容及增渗范围的分析模型；对溶腔非盐盖层/夹层系统开展密闭性的宏观、微细观、专项指标研究，探明盖层/夹层的封闭机理和密闭性影响的主控因素；最后结合储库密闭性现场测试对新提出的密闭性分析模型和评判准则的可靠性和适用性进行验证。项目研究将为我国盐穴储气库密闭性评价体系的建立提供基础理论和方法，从而为盐穴储气库选址、设计和运行规避渗透灾害提供理论和支撑。

本项目历时四年，通过试验研究、理论分析、现场测试以及数值模拟，对我国在建的典型盐矿开展了应用基础研究，建立了地下盐穴储气库密闭性评价指标体系，取得了诸多研究成果，圆满的完成了项目既定计划，达到了项目研究目标。本项目开展在模拟腔体实际运行条件下的渗透演化规律研究，揭示了层状盐岩中储气库渗透特征；通过试验研究和理论分析，探明了盖/夹层宏细封闭机制和建立了封闭能力主控评价指标，并指导现场进行应用，为今后盐穴储气库的密闭性评价奠定了良好的基础。