A method to experimentally investigate injection-induced activation of fractures  

作　　者：Changdong Ding Yang Zhang Qi Teng Dawei Hu Hui Zhou Jianfu Shao Chuanqing Zhang 

机构地区：[1]State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,430071,China [2]University of Chinese Academy of Sciences,Beijing,100049,China [3]CNPC Engineering Technology R&D Company Limited,Beijing,102206,China [4]PetroChina Tarim Oilfield Company,Korla,841000,China [5]University of Lille,LaMcube,CNRS FRE 2016,59000,Lille,France

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2020年第6期1326-1332,共7页岩石力学与岩土工程学报（英文版）

基　　金：The financial support by the National Key Research and Development Program of China(Grant No.2018YFC0809601);the National Natural Science Foundation of China(Grant No.51779252);the Major Technological Innovation Projects of Hubei,China(Grant No.2017AAA128);the Key Projects of the Yalong River Joint Fund of the National Natural Science Foundation of China(Grant No.U1865203)for this work are gratefully acknowledged。

摘　　要：Natural fractures are generally well developed in most hydrocarbon and geothermal reservoirs,which can produce complex fracture networks due to the activation of fractures during hydraulic stimulation.The present paper is devoted to developing a method to investigate the activation characteristics of fracture under injection-shearing coupled condition at laboratory scale.The fluid is injected into the single-fractured granite until the fracture is activated based on the triaxial direct shear tests.The results show that injection process can significantly influence the shear stress distribution field,resulting in release of shear stress and relative slip between the opposite sides of the fractured surface.The injectioninduced activation of fracture is strongly dependent on the stress states.When the normal stress increases,the injection-induced activation pressure increases,and the comparatively high normal stress can restrain the fracture activation.The fracture deformation mechanisms during fluid injection are also discussed preliminarily with the experimental data.The sensitivity of shear stress to fluid injection increases with increase of shear stress level,while it decreases under high normal stress.The results can facilitate our understanding of the natural fracture activation behavior during fluid pressure stimulation.

关 键 词：Natural fracture Fluid injection Induced activation Triaxial direct shear test Hydraulic fracturing 

分 类 号：TE31[石油与天然气工程—油气田开发工程]