摘要
高频扭转冲击钻井是一种能大幅提高钻井效率的新兴钻井技术,但由于对其破岩机理认识不清,使得高频扭转冲击钻井技术未能在国内推广应用。基于弹塑性力学和岩石力学,采用Drucker-Prager准则作为岩石的本构关系,塑性应变作为岩石破碎的失效判据。通过有限元方法建立全尺寸PDC钻头动态破岩的非线性动力学三维仿真模型,分析了高频扭转冲击作用下硬地层中钻头的动态破岩过程。结果表明,高频扭转冲击钻进硬地层时拉应力与压应力区域交叉出现且以拉应力为主,较以压应力为主的常规钻进可大幅提高钻头的机械钻速;高频扭转冲击钻进有效地减弱了硬地层中钻头处的粘滑振动,大大地提高了钻头的破岩效率。研究成果有助于深化对高频扭转冲击破岩的认识,为高频扭转冲击钻井技术的应用提供理论依据。
High frequency torsional impact drilling is a new emerging drilling technology,it can enhance the drilling efficiency greatly.But it is not popularized due to ignorance of its rock breaking mechanism.A 3D non-linear dynamic simulation model of dynamic rock breaking with a full gauge PDC bit was established with the finite element method based on elastoplastic mechanics and rock mechanics.The constitutive relation of rock was controlled with Drucker-Prager law and plastic strain was adopted to judge the rock breaking.The dynamic rock breaking process of the bit under high frequency torsional impact in tough formation was analyzed.Results showed that most of rock elements are damaged by tension stress,the ROP is raised greatly;the high frequency torsional impact weakens stick-slip vibration effectively and increases the rock breaking efficiency greatly.The results provided a theoretical basis for deep understanding and popularizing the high frequency torsional impact drilling technology.
出处
《振动与冲击》
EI
CSCD
北大核心
2012年第20期75-78,109,共5页
Journal of Vibration and Shock
基金
国家自然科学基金优秀青年科学基金项目(51222406)
国家自然科学基金项目(50804040)
四川省杰出青年学术技术带头人资助计划项目(2011JQ0020)
关键词
硬地层
钻井技术
高频扭转冲击
岩石破碎
机械钻速
tough formation
drilling technology
high frequency torsional impact
rock breaking
rate of penetrate（ROP）
