摘要
最大水平主应力测量结果误差较大是水压致裂地应力测量方法中存在的突出问题。在梳理国内外水压致裂地应力测量规程或建议方法的基础上,对比分析用于计算最大水平主应力的几个主要公式之间的差异及其适用性,并以测试系统柔度为主要影响因素,较为细致和深入地分析影响最大水平主应力计算精度的误差来源及其物理机制。在此基础上,以甘肃北山花岗岩钻孔获取的深孔水压致裂实测数据为例,基于KGD理论模型对裂缝重张过程进行数值分析,定量研究系统柔度对最大水平主应力计算结果的影响。以剔除柔度影响因素的理论计算值为“修正值”,给出孔深18~930m深度范围共计6个测段的实测数据和“理论修正值”,结果表明,受系统柔度影响,随测试深度增加,最大水平主应力测试结果误差逐渐增加。当测试深度为930 m时,测量结果的相对误差为24.55%。研究结果可为相关工程应用中最大水平主应力测量结果误差问题提供参考,也为开展水压致裂地应力测量的误差分析,以及进一步提升测量结果的可靠性提供一种新的研究思路和技术途径。
The large error in the results of the maximum horizontal principal stress is a prominent problem in the in-situ stress measurement by hydraulic fracturing method.In this paper,the differences and applicability of several main formulas used to calculate the maximum horizontal principal stress are compared and analyzed on the basis of the domestic and foreign hydraulic fracturing in-situ stress measurements regulations or suggested methods.Taking the test system compliance as the main influencing factor,the error sources and physical mechanism that affect the calculation accuracy of the maximum horizontal principal stress are analyzed in detail and depth.On this basis,taking the measured hydraulic fracturing data of the deep-hole obtained from the granite borehole in Beishan,Gansu as an example,the fracture reopening process is numerically analyzed based on the KGD theoretical model,and the influence of system compliance on the calculation result of the maximum horizontal principal stress is quantitatively studied.Taking the theoretical calculation value of eliminating the influence factors of compliance as correction value,the measured data and heoretical correction valueof 6 testing intervals in the hole depth range of 18-930 m are given.The results show that the error of the maximum horizontal principal stress measurement results increases gradually with the increase of test depth due to the influence of the test system compliance.When the test depth is 930 m,the relative error of the measurement results is 24.55%.The research results can provide a reference for the error problem of the maximum horizontal principal stress measurement results in relevant engineering applications,also provide a new idea and technical approach for the error analysis and further improvement of the reliability of the hydraulic fracturing in-situ stress measurements.
作者
杨跃辉
孙东生
秦向辉
李阿伟
孙炜锋
张重远
李冉
孟文
陈群策
YANG Yuehui;SUN Dongsheng;QIN Xianghui;LI Awei;SUN Weifeng;ZHANG Chongyuan;LI Ran;MENG Wen;CHEN Qunce(Institute of Geomechanics,Chinese Academy of Geological Science,Beijing 100081,China;Engineering Technology Innovation Center of In-situ Stress,Ministry of Natural Resources,Beijing 100081,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2024年第S01期3385-3396,共12页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金面上项目(42174122)
中央级公益性科研院所基本科研业务费项目(DZLXJK202201)
关键词
岩石力学
水压致裂法
系统柔度
重张压力
最大水平主应力
误差分析
rock mechanics
hydraulic fracturing method
test system compliance
re-opening pressure
the maximum horizontal principal stress
error analysis
