机液控制可变径扶正器的结构及应用研究

Structure and Application of the Centralizer with Its Diameter Being Changed by Mechanical hydraulic Control

在定向钻井中，造斜、稳斜及降斜是主要的工艺过程．目前在实际钻井时，实现这几个工艺过程，需要通过起下钻具，改变钻具组合来完成，这样就使得钻井作业辅助时间增长．本文将介绍一种机液控制的可变径扶正器．该扶正器的特点是工作时直径可调节，因而，不需要起下钻就可实现钻具组合的改变，从而完成造斜，稳斜及降伴等工艺过程．使用该扶正器将大大节约钻井成本，提高钻进速度．给出了这种可变径扶正器的主要结构设计、工作原理、主要的水力计算方法及简单的应用操作．通过计算分析可知：该扶正器可在任意深度的井段内实现变径，从而完成特殊作业要求．

Deflecting,hold angle and drop angle are the main technologies in directional drilling.At present,these technologies are realized by changing the bottom hole assembly (BHA),but frequent trippings result in the increase of anxiliary time in drilling operation.The authors designed a new kind of centralizer whose diameter can be changed by mechanical hydraulic control.Different BHA ′s can be got only by changing the diameters of the centralizers in different depth without trippings.The drilling speed is thus increased and the cost of drilling is lowered.In this paper,the structure,working principle and main hydraulic calculation of the centralizer are introduced.Calculation result shows that the diameter of the centralizer can be changed in any depth.