锥形齿旋冲及扭冲的破岩过程与破岩效率分析

Rock Breaking Process and Efficiency Analysis of Conical Cutting Teeth under Rotary and Torsional Impact

胡思成 管志川 路保平 梁德阳 呼怀刚 闫炎 陶兴华

HU Sicheng GUAN Zhichuan LU Baoping LIANG Deyang HU Huaigang YAN Yan TAO Xinghua

中国石油大学（华东）石油工程学院，山东青岛 266580 山东省深地钻井过程控制工程技术研究中心，山东青岛 266580 中国石化石油工程技术研究院，北京 102206

School of Petroleum Engineering, China University of Petroleum(East China), Qingdao, Shandong, 266580, China Shandong Ultra-Deep Drilling Process Control Technology Research & Development Center, Qingdao, Shandong, 266580, China Sinopec Research Institute of Petroleum Engineering, Beijing, 102206, China

为了解锥形齿在旋转冲击和扭转冲击载荷作用下的破岩过程和破岩效率，采用数值模拟和试验数据验证的方法，研究了2种破岩方式下不同冲击幅值和冲击频率对应的岩石内部应力变化、岩石损伤特征、岩石破碎体积和破碎深度、破岩比功。数值模拟分析结果表明，锥形齿在旋转冲击和扭转冲击破岩过程中均表现为切削齿侵入岩石、岩石损伤贯通裂纹萌生、岩石损伤贯通裂纹扩展、裂缝贯通岩屑崩落4个阶段，拉应力是引起岩石内部到表面贯通裂缝产生的主要原因，压剪应力是岩石内部出现损伤和形成微裂纹的主要原因。随着冲击幅值和冲击频率增大，旋转冲击和扭转冲击破岩方式下，锥形齿破碎岩石的体积都会增大，但当冲击幅值和冲击频率增加到一定值时，岩石破碎体积的增加趋势趋于平缓；锥形齿旋转冲击破岩方式下的最大破碎体积高于扭转冲击破岩方式。常规切削、旋转冲击和扭转冲击3种破岩方式下，锥形齿常规切削的破岩比功最大，不同冲击幅值和冲击频率条件下，锥形齿扭转冲击破岩方式下的破岩比功普遍比旋转冲击破岩方式低。

In order to gain a better understanding of the rock-breaking process and efficiency of conical cutting teeth under rotary and torsional impact loads, numerical simulation and experimental data verification were conducted to study the rock’s internal stress changes, damage characteristics, breaking volume, depth and rock breaking specific work by the two methods at different impact amplitudes and frequencies. The numerical simulation and analysis results showed that both the rock-breaking processes of conical cutters under rotary impact and torsional impact could be divided into four stages: cutter intruding into rock, damage through crack initiation, damage through crack propagation, and rock cuttings avalanche. The tensile stress is the main reason for the cracks from the inside to the surface of rock, and the internal damage and micro-cracks appear mainly due to compressive shear stress. With the increase of impact amplitude and impact frequency, the broken volume of rock will increase in both the two ways. When the impact amplitude and frequency are increased to certain values, the increase of rock-breaking volume tends to be mild, and the maximum rock-breaking volume under rotary impact is higher than that under torsional impact. Among the three rock breaking methods - conventional cutting, rotary impact and torsional impact - the rock breaking specific work of conventional cutting is the greatest, and the rock breaking specific work under the conditions of different impact amplitudes and frequency of torsional impact is generally lower than that of rotary impact.

国家科技重大专项“机械式旋转冲击钻井工具及小井眼复杂环境旋冲钻井工具研制”（编号：2016ZX05021-003-002HZ）资助

https://doi.org/10.11911/syztjs.2021035