摘要
黏滑振动是PDC钻头钻井过程中一种常见的现象,它会引起钻头过早失效、钻进效率低等问题,使钻井成本升高。在钻头上部安装一套扭力冲击器,可在钻进过程中给钻头提供一个周期性的高频周向冲击载荷,减少扭矩的积蓄时间,减轻PDC钻进过程黏滑振动。通过对周向扭力冲击器作用下的PDC钻头在钻井过程中的工况分析,结合钻头钻进力学分析和岩石破碎学,建立了PDC钻头在周向往复循环冲击载荷作用下的破岩力学模型。对其数值仿真后结果表明,在一定的冲击扭矩作用下,钻进岩石内聚力为40 MPa的岩层时,卡钻时间减少了51%。这说明对钻头施加周向冲击后可以减轻黏滑振动。研究结果可为周向扭力冲击器在PDC钻头钻井作业过程中的使用提供理论支撑。
Stick-slip vibration is a common phenomenon in the process of PDC drilling,and it can cause the premature failure and low drilling efficiency of PDC bit.And as a result,the drilling cost is increased.If a set of torsion impactor is installed at the top of the drill bit,it will apply a cyclic high-frequency circumferential impact load to the drill bit during the drilling,so that the torque accumulating time can be reduced and the stick-slip vibration in the process of PDC drilling can be mitigated.The behavior of PDC bit under the effect of circumferential torsion impactor in the process of drilling was analyzed.Then,combined with bit drilling mechanics analysis and rock fragmentation,the rock-breaking mechanical model of PDC bit under the effect of circumferential cyclic impact load was established.Its numerical simulation results show that under the effect of a certain torque impact,the pipe sticking time is reduced by 51%when internal cohesion of the drilled rock is 40 MPa.It is indicated that stick-slip vibration can be mitigated by applying the circumferential impact to PDC bit.The research results provide the theoretical support for the application of circumferential torsion impactor in the drilling process of PDC bit.
作者
李美求
李嘉文
李宁
罗竞波
LI Meiqiu;LI Jiawen;LI Ning;LUO Jingbo(Institute of Strength and Vibration of Mechanical Structures,Yangtze University,Jingzhou 434023,Hubei,China)
出处
《石油钻采工艺》
CAS
CSCD
北大核心
2018年第3期287-292,共6页
Oil Drilling & Production Technology
基金
中国石油科技创新基金计划项目"液动周向扭矩冲击破岩技术研究及应用"(编号:2015D-5006-0310)
关键词
扭力冲击器
PDC钻头
黏滑振动
周向振动
破岩
torsion impactor
PDC bit
stick-slip vibration
circumferential vibration
rock-breaking
