结构力学分析方法在南海水平井钻进预测中的应用

本文探讨了结构力学分析方法-非线性有限元性在预测水平井钻进中的工程应用，在钻探水平井尤其是大位移水平井中，事先较准确地预测出钻柱的钻进扭矩及钻头前进的方向，是取得水平井成功的关键条件之一。利用非线性有限元理论，着重分析了水平井实际钻进中的钻柱大变形非线性及钻柱与井壁的接触非线性问题，并导出了一套非线性有限元钻柱力学模式，在此基础上编制了一套非线性力学计算程序软件，并在海洋石油南海西部石油公司一个钻井平台水平井钻井进行了五口井的实际验证，获得了一些有启迪性的结论。

Reseach of torque and direction of bit inhorizontal well by method of nonlinear limited element

This paper discusses the apply in the drilling engineering by the method of nonlinear limited element, which is about the torque of string and direction of bit and while drilling. A key to successfully drill a horizontal well is to forecast the direction of bit and the torque of drillingrod. The theme analyses two questions of nonlinear mechanics while procedure of drilling horizontal well actually, that one is nonlinear in the case of the large deformation of rod and another is nonlinear in the case of the connect between rod and wall of well. The paper derived a serial of formulates independently about drilling mechanics of the nonlinear limited element. It was made that computer program of mechanics of drilling string by the nonlinear limited element and had been operated in 5 wells where is weizhou of China, which is belong to a flat in WEST COMPANY CHINA NATIONAL OFFSHORE OIL CORPORATION. It showed some conclusion for the procedure of drilling