【作者】 陈剑文；

【导师】 杨春和；

【作者基本信息】 中国科学院研究生院（武汉岩土力学研究所） ， 岩土工程， 2008， 博士

【摘要】 温度对盐岩的力学性质影响研究是分析、评价盐岩地层中的天然气储备、压气蓄能以及核废料处置等硐室的安全、稳定性基础。虽然前人,尤其是国外对此进行了大量的实验,但主要是围绕稳态蠕变速率而开展,至于温度对盐岩的损伤、屈服以及塑性变形的影响并没有详细、深入研究。此外,储气库运行过程中的热工分析是进行储气库管理以及稳定性分析的基础,对此目前也没有很好的分析方法。针对这些问题,本文结合实验研究、细观机理分析以及数值模拟等方法对上述问题进行了分析、研究,主要包括如下几个方面:(1)采用超声波技术和频谱分析理论,研究了盐岩在升温过程和温度循环过程中的超声波波速、动弹性参数变化规律,以及热损伤随温度和循环次数、温度幅值的演化规律。(2)在分析盐岩热损伤机理的基础上,通过数值模拟研究了盐岩的杨氏模量和线性膨胀系数以及材料的不均匀性(形状参数m )对热损伤的影响规律。(3)通过应城盐岩在不同温度、围压下的三轴压缩实验,获得了应城盐岩的压缩-扩容边界,提出了适合性更强的压缩-扩容边界表达式。根据压缩-扩容边界带理论,提出采用压缩-扩容接近度来分析盐岩储气库的密闭性,给出了盐岩压缩-扩容接近度的定义、表达式,并对金坛设计溶腔进行了密闭性分析。(4)根据实验结果,拟合了应城盐岩在不同温度下的剪切屈服面。从细观角度分析了盐岩屈服应力的组成部分,给出了屈服应力的表达式,并分析了温度对盐岩屈服应力的影响规律。(5)借鉴固体位错理论,建立了基于细观变形机理(位错和亚晶化)的盐岩塑性本构方程,通过实验验证,该模型是合理的。基于本文所提模型,分析了温度对盐岩塑性变形的影响规律和机理。(6)基于变质量热力学理论和前人的研究成果,给出了可以考虑三维任意溶腔形状和围岩温度场的盐岩储气库热工计算模型及其求解方法,并对金坛设计储气库进行了单腔注、采气过程的热工计算。更多还原

【Abstract】 Researching the effect of temperature on mechanical behavior for salt is the basis of analyzing and estimating security and stability for caverns in deep salt formation for natural gas storage, compression air energy storage and radioactive disposal. The previous many works were most focused on the effect on secondary creep rate. So far, the effects of temperature on damage, yield and plastical deformation of salt are not particularly researched. Additionally, engineering thermal analysis is important basic of management and stability analysis of cavern for natural gas storage, but studies on the engineering thermal analysis are not sufficient. The shape of the cavern is often assumed as cylinder or sphere. In some works, the engineering thermal analysis is based on the rigid container variable thermodynamics theory. Aiming at above problems, this dissertation analyzed the experiment outcome of salt heating tests and compression tests under different confining pressure and temperature, the micro-mechanism of deformation. For the engineering thermal analysis, the energy and the mass of the gas in cavern, the thermal field of the wall rock and the gas flowing in the well are also analyzed. The main research works of this dissertation are as follows:1. With the ultrasonic technology and spectrum analysis, the ultrasonic velocity, dynamical elastic parameters and the thermal damage evolution of rock salt under different temperature condition, including rising temperature and cycling temperature of different amplitude, are researched.2. Based on thermal damage mechanism for rock salt, effect of the material parameters, Young’s modulus and linear expansion coefficient , on the thermal damage evolution is simulated. The effect of shape parameter(of Weibull distribution function) on thermal damage also analyzed by numerical simulation.3. The compaction-dilatancy boundaries(CDB) of Yingcheng Salt under different temperature are obtained form tri-axial compression datum and the modified CDB function also proposed. Based on the compaction-dilatancy theory for salt, sealability analysis of cavern for gas storage in salt formation by dilatancy approach index(DAI) is proposed, and the DAI definition and expression are also given. With the method, sealability of Jintan designed cavern is analyzed.4. The yield curves on p-q plane under different temperature are obtained with the tests for Yingcheng Salt. According to the micro-deformation mechanism, the yield stress of salt is analyzed and the yield stress function is introduced. Based on the equation, effect of temperature on the yield stress is analyzed.5. According to the composition theory and the dislocation and subgrain evolution of salt during the deformation, the plasticity constitutive model alt is made and the model is also validated by laboratory tests. Effect of temperature on plastical deformation of salt is analyzed by the proposed constitutive model.6. Based on the variable mass thermodynamics and former studies, engineering thermal analysis model for natural gas storage in deep salt formation and the solution of the model are presented. The presented model can be used for actual three dimension shape of the cavern and the thermal field of the salt formation. Engineering thermal analysis for Jintan single cavern during injection and production is simulated using the presented model and some results are concluded.更多还原