管内可控铰接柔性结构双层接触非线性力学分析

Two-layer Contact Nonlinear Mechanics Analysis of Controllable Universal Joint Flexible Structure in the Tubes

管内可控万向铰接柔性细长结构是超短半径侧钻水平井的特有结构。考虑可控万向铰结构中的机构问题、结构不连续和开槽不完整结构的三体两层接触问题,将空间梁单元、万向铰单元、刚性梁单元和梁梁接触单元相结合,建立了管内可控万向铰接柔性结构双重接触非线性有限元模型及数值计算方法。与有解析解的算例进行比对,计算结果吻合较好。通过对超短半径水平井造斜钻进时的柔性钻具进行力学分析,得到了柔性钻具受力变形状态、载荷传递规律及其与井壁之间的接触力分布规律。

The controllable universal joint flexible slender structure in the tubes was an unique structure of the ultra-short radius horizontal wells.Considering the mechanism problems of controllable universal joint structures where the three-body two-layer contact problems of structural discontinuity and slotted incomplete structure,the 3-D beam elements,universal joint elements,rigid beam elements and the beam-beam contact elements were combined.A two-layer contact nonlinear finite element model of a controllable universal joint flexible structure in the tubes was established and a numerical calculation method was carried out.It was compared with an analytical solution by an example.The calculation results are in good agreement.The mechanics analysis of the flexible drilling tools in oblique drilling of ultra-short radius horizontal wells was carried out.The deformation state,the law of load transmission of the flexible drilling tools and the distribution law of the contact forces with the borehole walls were obtained.