旋转导向工具下入通过性研究

Study on the Running-in Passing Ability of Rotary Steerable Tool

研究旋转导向工具通过大曲率井段的力学特征,对于水平井钻井设计和旋转导向工具选择有重要意义。为此,基于纵横弯曲梁理论提出了一种受迫变形条件下的刚性旋转导向工具下入能力分析方法,并考虑临界压力和井壁约束下的工具弯曲极限状态,给出了工具的挠度变化范围和下入安全性准则。采用过尺寸钻头复合钻进方式,旋转导向工具通过能力有大幅提升;对旋转导向工具实际下入过程进行通过安全性分析计算,考虑井壁作用和上部轴向力作用,对管柱施加一个轴向外载荷压力,得到实际下入过程的弯曲挠度值,校核旋转导向工具下入摩阻力和强度,工具可以安全下入,不会发生屈服破坏。研究结果表明,建立的计算模型有较高的准确性和较好的适用性,可以为现场钻井过程中大曲率井段旋转导向工具下入安全性评价提供指导。

The study of the mechanical characteristics of the rotary steering tool passing through the large curvature section is of great significance for the design of horizontal well drilling and the selection of rotary steering tools.Based on the theory of vertical and horizontal bending beam,a method for analyzing the pass-through capacity of rigid rotary steering tool under forced deformation is proposed.The bending limit state of the tool under the critical pressure and wellbore constraints is considered to give the deflection range of the tool and run-in safety guidelines.By adopting the compound drilling method and over-gauge bit,the passing capacity of the rotary steering tool is greatly improved.The pass-through safety of the actual run-in rotary steering tool is analyzed and calculated.Considering the effect of the wellbore and the upper axial force,an axial load is applied to the string to obtain the bending deflection during the string’s running in.The run-in friction and strength of the rotary steerable tool are checked.The tool can be safely run in without yield failure.The research results show that the model has good accuracy and applicability,and can provide guidance for the run-in safety of rotary steerable tools in large curvature well sections.