干热岩储层高温条件下岩石力学特性研究  

Study on rock mechanical properties of hot⁃dry rock reservoir under high temperature

作　　者：谭现锋 张强[1,2] 战启帅 李生海 江海洋 张帆 TAN Xianfeng;ZHANG Qiang;ZHAN Qishuai;LI Shenghai;JIANG Haiyang;ZHANG Fan(Shandong Provincial Lunan Geology and Exploration Institute(Shandong Provincial Bureau of Geology&Mineral Resources No.2 Geological Brigade),Jining Shandong 272100,China;Shandong Geothermal Clean Energy Exploration and Development Engineering Research Center,Jining Shandong 272100,China;No.1 Institute of Geology and Mineral Resources of Shandong Province,Jinan Shandong 250102,China;School of Civil Engineering Architecture&Environment,Hubei University of Technology,Wuhan Hubei 430068,China)

机构地区：[1]山东省鲁南地质工程勘察院(山东省地质矿产勘查开发局第二地质大队),山东济宁272100 [2]山东省地热清洁能源勘查开发工程研究中心,山东济宁272100 [3]山东省第一地质矿产勘察院,山东济南250102 [4]湖北工业大学土木工程与环境学院,湖北武汉430068

出　　处：《钻探工程》2023年第4期110-117,共8页Drilling Engineering

基　　金：国家自然科学基金项目“干热岩水力压裂-热冲击耦合机理及压裂效果评估”(编号:51979100)。

摘　　要：为了更准确掌握高温条件下干热岩储层的岩石力学性质,进一步指导干热岩钻井施工,通过室内试验进行了实时高温条件下的巴西劈裂试验、剪切试验、单轴压缩试验。单一试验采用同一钻孔同一深度采取的岩样,通过高低温箱控制器设置温度和恒温时间,以恒位移速率0.1 mm/min对试样进行加载,减少岩石宏观力学性质的离散性和试验过程偏差对试验结果的不利影响。试验样品为山东省文登—荣成—威海地区LGZK1井采取的二长花岗岩,通过获得试样破坏时的最大荷载值和变形数据,计算其抗拉强度、抗剪强度、抗压强度、弹性模量等力学性质参数,分析实时高温条件下岩石内部破坏机理和岩石强度差异。研究结果表明,在200℃以内,花岗岩的抗剪强度和单轴抗压强度升高、抗拉强度降低;随着温度的进一步升高,花岗岩的抗剪强度和单轴抗压强度降低,而抗拉强度持续降低;储层岩体温度和应力的升高,将使岩石的硬度增加、塑性增强。这些认识可为高热流花岗岩岩石力学性质的进一步研究提供基本参数,为高热流花岗岩型干热岩资源勘探开发过程中碎岩机具的选型、钻井工艺的选择、井壁稳定的控制等提供参考依据。In order to know more accurately the rock mechanical properties of hot‑dry rock reservoir under high temperature,and further guide the drilling work of hot‑dry rock,the real‑time Brazilian splitting test,shear test and uniaxial compression test under high temperature were carried out in laboratory.In a single test,rock samples taken from the same borehole and the same depth were loaded at a rate of 0.1mm/min by setting the temperature and holding temperature time using a high‑low temperature chamber,to reduce the adverse influence of the discretization of rock macro‑mechanical properties and the deviation of test process on the test results.The samples are monzonitic granite taken from the Well LGZK1 in the Wendeng-Rongcheng-Weihai area of Shandong province.Through obtaining the maximum load and deformation data of the samples at failure,the mechanical properties such as tensile strength,shear strength,compressive strength and elastic modulus are calculated,and the failure mechanism and strength difference of the rock under real‑time high temperature are analyzed.As a result,the shearing strength and uniaxial compressive strength of granite increased and the tensile strength decreased below 200°C.While the shear strength and uniaxial compressive strength of the granite decreased and the tensile strength continuously decreased with the increase of temperature.The increase of temperature and stress will increase the hardness and plasticity of the rock.It provides basic parameters for the study of rock mechanical properties of the high heat flow granite,and also provides a reference for the selection of rock‑crushing tools,drilling technology and wellbore stability in the exploration and development of high heat flow granite type hot‑dry rock resources.

关 键 词：干热岩储层 花岗岩 实时高温 巴西劈裂试验 剪切试验 单轴压缩试验 

分 类 号：P634.1[天文地球—地质矿产勘探] TE21[天文地球—地质学]