废弃油气藏气体能源存储过程中不同浸润界面类型的断层活化试验研究  

Experimental study on fault activation of different infiltration interface types in gas energy storage process of abandoned oil and gas reservoirs

作　　者：胡明慧 刘日成[1] 李树忱 朱欣杰 邱凯 HU Minghui;LIU Richeng;LI Shuchen;ZHU Xinjie;QIU Kai(State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)

机构地区：[1]中国矿业大学深地工程智能建造与健康运维全国重点实验室,江苏徐州221116

出　　处：《岩石力学与工程学报》2024年第1期75-89,共15页Chinese Journal of Rock Mechanics and Engineering

基　　金：江苏省科技厅科技项目–碳达峰碳中和科技创新专项资金项目(BK20220025);国家自然科学基金资助项目(51979272);江苏省自然科学基金项目(BK20211584)。

摘　　要：通过开展干燥、湿润和原油3种类型岩石结构面卸载诱发滑移的三轴力学试验,探究界面类型对岩石结构面活化过程的影响机制,揭示活化过程中结构面微观特征和宏观特性之间的内在关系。试验结果表明,岩石结构面的活化分为3阶段:稳定阶段、活化阶段和动态滑移失稳阶段。岩石结构面剪断剥落的岩屑随剪切滑动而产生层理状积聚,滑动面边缘损伤程度大于滑动面内部损伤程度。干燥界面试样试验后结构面的JRC降低了62%,大于湿润界面(33.6%)和原油界面(30.5%)试样。在干燥界面状态下,结构面上的微凸体自锁能力强,稳滑时的平均速率较低(0.13μm/s),黏滑时表面微凸体以脆性破坏为主,具有突发性,平均滑移速率为9.7μm/s,是稳滑时平均速率的74倍;在湿润界面状态下,水的存在促进了黏滑,黏滑时表面微凸体以延性破坏为主,速率的迁跃具有明显的爬坡和回落特征,剪切滑移期间产生的岩屑和水混合,增大了岩石上下表面接触面积,提高了分子间吸附力,强化了岩石结构面的摩擦强度;在原油界面状态下,岩石表面会附着一层胶质原油层,作为延性断层泥充填了岩石结构面上的凹凸空间,劣化了表面微凸体的硬度,降低了岩石结构面的摩擦强度。原油条件下结构面摩擦强化效果弱,自锁能力差,容易发生动态滑动。界面类型控制着摩擦因数增长幅度和动态滑移的起始速率,干燥、湿润和原油类型的岩石结构面在活化期间摩擦因数分别增长了5%,11.2%和0.7%,动态滑移的起始速率分别为1.1,0.27和0.023 mm/s。研究结果可为评价油气藏不同界面类型结构面的断层不稳定性提供理论依据,并对深入了解注采扰动诱发断层活化具有重要意义。Through conducting the triaxial unloading-induced slip tests of different types of rock structural planes with dry,wet and crude oil interfaces,the effect of interface types on the activation process of rock structural planes was explored,and the correlations between the microscopic characteristics and macroscopic performance of structural planes during the activation process were revealed.The results show that the activation of rock structural plane is divided into three stages,i.e.,stable stage,activation stage and dynamic slip instability stage.During shear sliding of rock structural plane,rock fragments resulting from the shearing and exfoliation of rock structural plane accumulate in the form of bedding,with greater damage observed at the edges of the structural plane compared to the interior.The JRC degradation rate of rock structural plane with dry interface is 62%after the triaxial tests,which is greater than that of dry interface(33.6%)and crude oil interface(30.5%).For the structural plane with dry interface,the asperities on the structural plane are strongly self-locked,and the average slip rate is low(0.13μm/s)in the stable stage.While in the stick-slip stage,the damage of the asperities on the structural plane is primarily brittle failure with suddenness,which leads to the average slip rate of stick slip reaching 9.7μm/s,74 times larger than that in the stable stage.For the structural plan with wet interface,the presence of water promotes the occurrence of stickslip events.During stick-slip,the damage of the asperities is mainly ductile failure,and the slip rate transition exhibits a sharp increase followed by a falling process.The mixing of rock fragment and water during shear slip increases the contact area between the adjacent structural plane,improves the intermolecular adsorption force,and strengthens the friction strength of the rock structural plane.For the structural plan with crude oil interface,a layer of colloidal crude oil is attached to the rock structural plane,which fills the void sp

关 键 词：岩石力学 界面类型 摩擦强度 滑移速率 

分 类 号：TU45[建筑科学—岩土工程]