深部原位应力环境下岩心饼化响应特征及反馈机制初探  

Preliminary study on response characteristics and feedback mechanism of core discing under deep in situ stress environment

作　　者：高明忠 何坤宸[4] 叶思琪 谢晶 杨本高[4] 李飞 郝海春 刘军军 杨尊东 GAO Mingzhong;HE Kunchen;YE Siqi;XIE Jing;YANG Bengao;LI Fei;HAO Haichun;LIU Junjun;YANG Zundong(State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,Shenzhen University,Shenzhen 518060,China;Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization,Shenzhen University,Shenzhen518060,China;Institute of Deep Earth Sciences and Green Energy,Shenzhen University,Shenzhen518060,China;College of Water Resource and Hydropower,Sichuan University,Chengdu 610065,China;State Key Laboratory of Coal Mining and Clean Utilization,Beijing100013,China;Chengdu Engineering Corporation Limited,Power China,Chengdu 611130,China)

机构地区：[1]深圳大学深地工程智能建造与健康运维全国重点实验室,广东深圳518060 [2]深圳大学广东省深地科学与地热能开发利用重点实验室,广东深圳518060 [3]深圳大学深地科学与绿色能源研究院,广东深圳518060 [4]四川大学水利水电学院,四川成都610065 [5]煤炭资源高效开采与洁净利用国家重点实验室,北京100013 [6]中国电建集团成都勘察设计研究院有限公司,四川成都611130

出　　处：《煤炭学报》2024年第4期1845-1859,共15页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(52225403);深圳市优秀科技创新人才培养基金资助项目(RCJC20210706091948015);煤炭资源高效开采与洁净利用国家重点实验室开放基金资助项目(2021-CMCU-KFZD001)。

摘　　要：地应力数据是一切深部工程的基础,传统测量方法获取的深部地应力信息效率低且未形成统一的规程规范,理论多是建立在诸多假设基础上,准确性难以评估。深部高地应力区通常有比较明显的岩心饼化特征,且不同应力环境产生的饼化形貌各异,通过岩心饼化反演地应力有望作为一种科学经济、方便快捷的地应力推算方法。试图通过探究深部原位应力条件下岩心饼化行为的力学机制,定义二维条件下的饼化烈度系数,以期实现基于岩心饼化特征计算原位地应力。以松辽盆地松科二井不同深度饼化岩心为研究对象,利用三维数据形貌采集系统获得了饼化岩心的宏观形貌,采用X射线衍射和岩相薄片等测试手段,分析得到了饼化岩心的矿物成分和微观结构;同时,基于离散元分析了不同应力条件下岩心的饼化行为力学机制。结果表明:松科二井饼化岩心形貌特征可分为破碎状、薄饼状、厚饼状、不规则状、半饼化状5类,端面断口形态包括错台状、平面状、灯盏状和花瓣状;岩饼的形貌特征与其埋藏深度、硬质矿物含量和破坏模式有较强的关联性;岩心饼化行为主要受到张拉应力控制,其裂隙起裂一般起始于岩心根部,由外向内向下呈凹陷状或平面状贯通岩心。水平主应力是影响岩心饼化行为的第一要素,高水平主应力能够诱发剧凹状的岩心断口和较宽的带状拉裂纹,垂直主应力是影响岩心饼化的次要因素,一般会抑制饼化行为的发生;钻进过程中岩心饼化行为的发生伴随着能量的规律性变化,其中总应变能呈阶梯状下降,耗散能呈对应的阶梯状上升,且总应变能的瞬时释放是造成岩心饼化的主要原因。研究成果有望为岩心饼化反演地应力提供新思路和有益借鉴。In-situ stress data are fundamental for deep engineering purposes.Traditional methods of measuring in-situ stress are inefficient and lack standardization.The theoretical framework is predominantly built on numerous assumptions,making it challenging to assess its accuracy.High in-situ stress at significant depths often leads to the formation of vari-ous core discing shapes.A more scientific,cost-effective,convenient,and rapid method for calculating in-situ stress in-volves the inversion of stress through core discing characteristics.To achieve this,understanding the behavior of core dis-cing under deep in-situ stress conditions is essential,as well as defining the intensity coefficient of core discing in two-di-mensional settings.By focusing on discing cores from varying depths in the Songke-2 well,their macro-morphology is captured using a three-dimensional data acquisition system.Additionally,the mineral composition and microstructure of the cores are analyzed through the X-ray diffraction and lithofacies thin section tests.Concurrently,the mechanical mech-anism governing core discing behavior under different stress conditions are studied using the discrete element method.The analysis reveals five distinct morphological types of discing cores in the Songke-2 well:broken,thin-disc,thick-disc,ir-regular,and semi-disc.The fracture patterns on the end face of the discs includes staggered step,plane,lamp,and petal formations.These morphological attributes are found to be closely linked to burial depth,mineral hardness,and failure mode.Core discing behavior is primarily controlled by tensile stress,with crack initiation typically occurring at the core's root and propagating outward in a concave or planar manner.The horizontal principal stress emerges as the primary factor influencing core discing behavior,leading to concave core fractures and wide-band tensile cracks,while the vertical prin-cipal stress serves as a secondary factor,generally inhibiting discing behavior.During drilling operations,the onset of dis-cing

关 键 词：岩心饼化 松科二井 颗粒离散元 宏细观特征 破坏模式 

分 类 号：TD313[矿业工程—矿井建设]