定向井的多层分注管柱串通过性分析

随着定向井注水层数增多，多层分注管柱串的通过性分析，是施工过程中确保油井安全、防止管柱失效的主 要方法，严重影响井下分注工艺的成功实施。以多个封隔器和配水器（5 个工具以上）组成的多层分注管柱串整体为分 析对象，充分考虑井眼轨迹、曲率、井径、地层摩阻、套管直径等因素的影响，采用力法和位移法，结合能量和动力学分 析方法，在三维空间下，分析管柱串与套管内壁之间的摩擦阻力与管柱串整体通过能力之间的关系，建立了一种可用 于定向井至水平井的多层分注管柱串在起下过程中的动态载荷和受力剖面模型，在井筒的最大曲率处，比较管柱串下 端的轴向作用力与摩擦阻力，从而实现对多层分注管柱的通过性分析。最后结合工程实例，对多层分注管柱串进行了 通过性和安全性分析，给现场作业提供了良好的工程指导。

The Pass-through Capacity Analysis for Multi-layer Injection Strings in#br# Directional Wells

With the increase of water injection layers in directional wells，the pass-through capacity analysis of injection strings becomes necessary. The pass-through capacity has great influence on the implement of multi-layer injection process，and on the safety of oil wells and malfunction prevention of the strings. The strings consist of at least 5 packers and distributors. After a comparison of the axial force with the friction of the injection string in maximum curvature section in the three-dimensional coordinate system，a new approach which can be used to analyze the pass-through capacity of injection string is given. In consideration of the factors such as borehole trajectory，curvature，borehole diameter，stratigraphic friction，casing diameter， and the relationship between the injection string friction and pass-through capacity，a model of dynamic load and stress profile has been established by using the mechanics and displacement method，combined with energy and kinetic analysis. The model can be used to analyze the process of running and pulling Multi-packer injection string in directional wells or horizontal wells. A case study is made to verify the pass-through capacity and safety of Multi-packer injection string which proved a good field guidance.