φ177.8 mm套管内大角度单弯螺杆下入阻力分析

Stress analysis of single-bending screw drill tool with large angle

钻中短半径水平井,在采用弯角较大的单弯螺杆钻具以满足高造斜率的需要时,由于套管内径较小,螺杆钻具钻头处位移比较大,螺杆钻具能否顺利通过直井段是钻中短半径水平井面临的一个重要问题。研究大角度螺杆钻具通过直井段时的力学特性对于合理选取螺杆钻具组合具有重要意义。文章采用有限元方法,以φ177.8 mm(7英寸)套管内单弯螺杆钻具为例,分析了单弯螺杆通过直井段时的应力分布规律及不同弯角大小对单弯螺杆通过直井段的影响。

To meet the demand of higher built-up rate, single-bending screw drill tool with large angle is used during the drilling of the moderate-and short-radius horizontal well. However, it is difficult to waltz through the horizontal section as the displacement in the place of bit is larger and ifs necessary to study the mechanical characteristics when getting across the horizontal section for the reasonable selection of crew drill tool assembly. With FEM and taking 7＂ casing for example, stress distribution when getting across the horizontal section is determined as well as the various bend angles effects on single-bending screw drill tool presented in this paper.