全尺寸PDC钻头旋转冲击破岩过程数值模拟  

Numerical Simulation of Rotary Impact Rock-Breaking Process of a Full-Size Drill Bit

作　　者：闫炎 韩礼红 刘永红[2] 杨尚谕 曹婧 牟易升 Yan Yan;Han Lihong;Liu Yonghong;Yang Shangyu;Cao Jing;Mou Yisheng(Tubular Goods Research Institute of CNPC;College of Mechanical and Electrical Engineering,China University of Petroleum(East China))

机构地区：[1]中国石油集团工程材料研究院有限公司 [2]中国石油大学(华东)机电工程学院

出　　处：《石油机械》2023年第6期36-42,共7页China Petroleum Machinery

基　　金：中国石油天然气集团有限公司科学研究与技术开发项目“油气井套损评价与修复关键技术研究”(2021DJ2705);“井筒完整性关键理论与控制技术”(2021DJ4403)。

摘　　要：旋转冲击破岩机理作为旋转冲击钻井技术的关键基础问题,始终未能得到很好的解决,限制了旋转冲击钻井技术的推广与应用。为了揭露旋转冲击破岩过程,基于有限元方法,依据旋转冲击破岩试验数据,建立并验证了全尺寸PDC钻头旋转冲击破岩数值模型及模拟方法,利用该模拟方法分析了全尺寸PDC钻头在常规破岩与旋转冲击破岩方式下岩石应力的变化情况。分析结果表明:常规破岩岩石的损伤主要发生在齿底与齿前,旋转冲击破岩岩石的损伤主要发生在齿底、齿前与齿周;在冲击力增大阶段,齿前岩石主要受拉、剪作用;在冲击力衰减阶段,齿前岩石主要受压、剪作用;且不同岩石类型的冲击载荷与冲击频率的最佳组合并不一致。所得结论可为旋转冲击钻井技术的推广提供一定的理论支撑。As the key fundamental aspect of rotary impact drilling technology,the mechanism of rock breaking has not been well demonstrated,which limits the application of this technology.To illustrate the rotary impact rock-breaking process,the numerical simulation model and method of rotary impact rock-breaking of full-size drill bits were established and verified by using the finite element method and the data of rotary impact rock-breaking experiments.The method was used to analyze the variation of rock stress under conventional rock-breaking and rotary impact rock-breaking.The results show that the rock damage mainly occurs at the bottom and front of the bit cutter under conventional rock-breaking,and at the bottom,front and circumference of the cutter under rotary impact rock-breaking.In the stage of increasing impact forces,the rock at the front of the cutter is mainly subjected to tensile and shear stresses.In the stage of decreasing impact forces,the rock at the front of the cutter is mainly subjected to compressive and shear stresses.The optimal combination of impact load and impact frequency varies with rock types.The research findings provide a theoretical support for promoting the rotary impact drilling technology.

关 键 词：全尺寸PDC钻头 旋转冲击 破岩过程 岩石应力 冲击力 

分 类 号：TE921[石油与天然气工程—石油机械设备]