沉渣颗粒影响下盐穴储气库变形破坏热力耦合分析  

Thermo-mechanical coupling analysis of deformation and failure of salt cavern UGS under the influence of sediment particles

作　　者：张华宾[1] 余豪毅 王来贵[1] 完颜祺琪[2] 冉莉娜[2] ZHANG Huabin;YU Haoyi;WANG Laigui;WANYAN Qiqi;RAN Lina(School of Mechanics and Engineering,Liaoning Technical University,Fuxin,Liaoning 123000,China;PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China)

机构地区：[1]辽宁工程技术大学力学与工程学院,辽宁省阜新市123000 [2]中国石油勘探开发研究院

出　　处：《天然气工业》2024年第12期137-150,共14页Natural Gas Industry

基　　金：辽宁省自然科学基金计划面上项目“流变—注采气扰动下高杂质盐矿老腔围岩损伤机理研究”(编号:2023-MS-315);国家自然科学基金青年项目“基于应变空间的盐岩蠕变全过程变形规律及演化模型研究”(编号:51504124)。

摘　　要：盐穴储气库注采气时腔内气体质量、压力和温度不断变化,动态内边界条件对围岩的影响较大,围岩局部可能产生大的变形和破坏,可威胁到盐穴储气库的安全稳定运行。为此,考虑温度、流体以及沉渣对围岩力学作用机制的不同,基于热力耦合和FLAC3D-PFC3D耦合方法,对注采气条件下的围岩位移、应力和塑性区分布及其变化特征进行了研究。研究结果表明:①随着采气和注气的进行,盐腔顶板竖向位移的绝对值逐渐增大,围岩塑性破坏范围逐渐扩大;②沉渣颗粒对围岩的影响具有一定的空间效应,距离沉渣颗粒越远的围岩变形和塑性破坏范围越大;③对于采气过程,沉渣颗粒的粒径和初始孔隙率越大,则腔顶围岩竖向位移和腔腰围岩第一主应力的代数值越小,围岩的塑性破坏范围越小;④对于注气过程,沉渣颗粒的粒径和初始孔隙率越大,则腔顶围岩竖向位移的代数值越大,腔腰围岩第一主应力代数值越小,围岩的塑性破坏范围越大。结论认为:①沉渣颗粒细观结构对围岩变形、应力以及塑性破坏区有重要影响,在实际工程应用中,建议采用离散元热力耦合方法精细刻画沉渣颗粒体系来评估其对围岩的影响;②沉渣颗粒影响下盐穴储气库变形破坏热力耦合分析,对我国盐穴储气库建设、沉渣利用、稳定性评价具有指导意义。During gas injection and production in salt cavern UGS,gas quality,pressure and temperature in the cavity change constantly,and the dynamic internal boundary conditions have a great influence on surrounding rocks,so the surrounding rocks may be locally subjected to large deformation and failure,which can threaten the safe and stable operation of salt cavern UGS.In view that temperature,fluid and sediment have different mechanical mechanisms to surrounding rocks,this paper studies the distribution and variation characteristics of the displacement,stress and plastic zone of surrounding rocks under the condition of gas injection and production based on thermo-mechanical coupling and the FLAC3D-PFC3D coupling method.The following results are obtained.First,as gas production and injection continues,the absolute vertical displacement of salt cavity roof increases gradually,and the plastic failure range of surrounding rocks expands gradually.Second,the influence of sediment particles on the surrounding rocks has a certain spatial effect,and the farther away from the sediment particles,the greater the deformation and plastic failure range of the surrounding rocks.Third,for the gas production process,the larger the size and initial porosity of sediment particles,the smaller the algebraic value of the vertical displacement of surrounding rocks at the top of the cavity,the algebraic value of the first principal stress of surrounding rocks at the waist of the cavity,and the plastic failure range of the surrounding rocks.Fourth,for the gas injection process,the larger the sediment particle size and initial porosity,the larger the algebraic value of the vertical displacement of surrounding rocks at the top of the cavity,the smaller the algebraic value of the first principal stress of surrounding rocks at the waist of the cavity,and the larger the plastic failure range of the surrounding rocks.In conclusion,the mesostructures of sediment particles have an important effect on the deformation,stress and plastic failure zone of su

关 键 词：连续—非连续耦合 热力耦合 盐岩储气库 颗粒材料计算力学 沉渣 围岩变形和破坏 时间效应 注采气 

分 类 号：TE822[石油与天然气工程—油气储运工程]