极端条件下特深井钻柱纵横扭耦合非线性振动研究

深部大陆科学特深井钻探及石油钻采工程施工中，钻柱不可避免地发生非线性振动，强烈的振动会导致灾难性的后果。针对极端条件（高温高压）下深部大陆科钻万米钻柱系统的纵横扭耦合非线性振动问题，本项目将考虑钻柱与井壁接触等约束条件，建立钻柱的耦合非线性振动的简化连续体模型，给出模型稳态解存在条件，并拟将Galerkin法与牛顿-谐波平衡方法相结合来构造高精度解析逼近解；建立并求解复杂的钻柱系统多体动力学模型，运用可视化技术展现钻柱钻井时的运动状态与非线性动力学特性；通过把理论模型与试验数据相比较来校正模型，使理论模型更符合实际。将进一步准确分析和描述钻柱失效机理，发展钻柱非线性振动理论，结合商业软件进行二次开发，编写用于计算、模拟极端条件（高温高压）下特深井钻柱动力学行为的程序模块；再依据地层性质等相关数据，优化超深井钻具组合，指导工程实际。

The nonlinear vibration of drill string in practical ultra-deep well for Deep Continental Scientific Drilling and petroleum engineering is inevitable. The strong oscillation will lead to disastrous consequences. The project is focused on the problems of coupled axial-transverse-torsional vibration of the deep Continental Drilling System with complex mechanical, temperature and pressure conditions. Considering the contact of drill strings and wellbore, the project will construct the nonlinear coupled vibration continuum model of the drill string. The existence conditions of steady-state solutions in the model are presented. Galerkin method and Newton-Harmonic method will be used to establish analytical approximate solutions with high precision.Based on drill strings and wellbore interaction, the complicated multi-body nonlinear dynamics model of drill strings will be presented and solved. Relying on the High Performance Computing Center of our university to simulate the state of drill string while drilling, the project will show the nonlinear dynamic characteristics of drill string. What’s more, compared to laboratory test and the practical data of " Songke 2 wells", the theoretical model will be corrected and more suitable to practical engineering. The project will promote the further accurate analysis and description of the drill-string failure mechanism, and develop the nonlinear vibration theory of the drill-string. The program will be developed to calculate response parameters and simulate the dynamic behavior of the drill string for the ultra deep well. According to the relevant data of the formation properties, optimize the combination of ultra deep well drilling tool for Chinese Deep Continental Scientific Drilling, and qualitatively guide the actual drilling engineering.