Micro-macro fracture mechanism of heterogeneous granite in percussive drilling

作     者：Wei-Ji Liu Yan-Fei Wang Zhao-Wang Dan Xiao-Hua Zhu 

作者机构：School of Mechatronic EngineeringSouthwest Petroleum UniversityChengdu610500SichuanChina Geothermal Energy Research CenterSouthwest Petroleum UniversityChengdu610500SichuanChina Powerchina Sinohydro Bureau 7 Co.LTDChengdu610500SichuanChina 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2023年第20卷第5期

页      面：3131-3142页

核心收录：

学科分类：0820[工学-石油与天然气工程] 082001[工学-油气井工程] 0819[工学-矿业工程] 08[工学] 070206[理学-声学] 0837[工学-安全科学与工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China(Grant No.52034006,No.52004229,No.52225401,No.52274231) Regional Innovation Cooperation Project of Sichuan Province(2022YFQ0059) Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(2020CX040301) Natural Science Foundation of Sichuan Province(23NSFSC 2099) Science and Technology Strategic Cooperation Project between Nanchong City and Southwest Petroleum University(SXHZ004) 

主　　题：Percussive drilling PFC Rock fragmentation characteristics Rock breaking efficiency 

摘      要：The conventional rotary rock breaking method faces a technical bottleneck in improving the rate of penetration(ROP)in deep hard *** drilling is the most potential approach to increase rock-breaking efficiency and ***,the rock-breaking mechanism of percussive drilling is still unclear enough,especially the micro-fracture mechanism of rock under confining pressure(under lateral pressure and hydraulic pressure).In this paper,the impact rock breaking experiments by four kinds of Polycrystalline Diamond Compact(PDC)cutters are carried out using a drop-weight impact testing machine and an acoustic emission(AE)recording system,the influence of parameters such as cutter shape,rake angle,and impact energy on rock-breaking are systematically *** study includes a numerical simulation to examine the process of crack initiation,propagation,and cuttings formation during the impact process with the consideration of confining *** results show the conicalshaped cutter is the most aggressive with high breaking *** penetration depth of the cutter is mainly influenced by the impact energy and cutter shape than the rake angle of the *** exists critical impact energy makes the rock breaking efficiency the *** critical impact energy is about 40 J when using the conical-shaped cutter with a rake angle of 15°.The rock mainly failed in tensile mode,and the inter-grain crack is the main *** pressure can inhibit the formation of horizontal cracks,while lateral pressure can inhibit the formation of vertical cracks and reduce the proportion of tensile *** research results can provide some reference and basis for improving the rock-breaking efficiency in deep hard formations.