套管钻井套管柱疲劳寿命预测分析研究

【作者】 张川；

【导师】 侯勇俊；

【作者基本信息】 西南石油大学 ， 机械工程， 2010， 硕士

【摘要】 套管钻井系统是一项新的钻井工艺技术。是指在钻进过程中,直接采用套管取代传统的钻杆向井下传递机械能量和水力能量,井下钻具组合接在套管柱下面,边钻进边下套管,完钻后作钻柱用的套管留在井内作完井用的技术。套管钻井将钻进和下套管合并成一个作业过程,不再需要常规的起下钻作业,与常规钻井技术相比可以节约大量的钻井工时,减少井下事故,降低钻井成本。与钻井中传统的钻杆相比,套管柱具有外径大、壁厚薄、环空间隙小等特点,其特有的性质对套管钻井作业以及后续作业具有重要的影响。其中,套管钻井中的管柱力学行为,尤其是旋转套管柱的动力学行为直接关系到套管柱在钻井过程以及后来的完井、固井中的安全和可靠性,并最终影响油气井的正常生产。因此,套管钻井中的力学行为分析对于套管钻井技术的发展具有重要意义。本研究借助于大型有限元软件ANSYS分析技术,运用现代实验及分析手段,以套管柱力学为基础,研究在套管钻井过程中的套管柱疲劳寿命问题,为有效地提高套管钻井的效率和保障后期开采施工提供理论依据,本文主要完成了以下工作：(1)完成了套管钻井中套管力学特性分析,包括套管钻井中套管几何特性分析,静态载荷下钻井套管柱的力学分析,动态载荷下钻井套管柱的动力学分析；(2)同时也完成了套管钻井套管柱疲劳寿命分析,包括疲劳问题、全寿命分析及使用有限元分析软件ANSYS完成了对套管柱的疲劳寿命分析；(3)套管钻井中套管磨损剩余强度分析,包括了磨损试验研究及套管磨损与剩余强度分析；(4)套管螺纹接头有限元分析,介绍了常用螺纹承扭结构,并建立了套管螺纹承扭能力有限元模型。总之本文结合钻井工程实际,分析套管柱的相关力学性能,为套管钻井技术的进一步发展,提供力学分析的技术支持,为套管钻井套管柱的研究提供了新的理论依据和方法。更多还原

【Abstract】 Casing drilling system is a new drilling process technology. During tripping in, it can directly adopt casing to transmit mechanical energy and hydraulic energy to the well downhole instead of traditional drill pipe. The downhole drill group is connected with the bottom of the casing string. Tripping in the casing while drilling in, after finishing drilling, the casing used as the drill string is left in the well to use as the technology of well completion. The casing drilling merges the drilling-in and tripping-in casing into one operating process. It doesn’t need conventional round trip any more. Compared with the conventional drilling technology, it can save much drilling working time and decrease downhole accident and cut down drilling cost.Compared with the conventional drill pipe during drilling, the casing string has these features:big outer diameter, thin wall thickness,small annular space, etc. Its special characters have important effect on the casing string operation and later operation. Among them, the pipe string mechanical action in the casing drilling, especially the dynamic action of rotary casing string directly ralates to the safety and reliability during drilling and in the later well completion and cementing. And it finally affects the normal production of oil/gas well. So the mechanical action analysis in casing drilling has an important sense on the development of casing drilling technology.This thesis analyzes technology with help of largy finite element software ANSYS. It uses modern experiment and analysis means to research the fatigue lifetime of casing string during casing drilling on basis of the casing string mechanics. To effeciantly raise the effeciency of casing drilling and supply theory basis of ensuring future production. This thesis mainly describes the following:(1) It finishes the casing mechanical character analysis during casing drilling, including the geometry character analysis, the mechanical analysis of drilling casing string under static load and dynamic load;(2) At the same time, it finishes the casing string fatigue lifetime analysis of casing drilling, including the fatigue problem, full lifetime analysis and the fatigue lifetime analysis about the casing string by using finite element analysis sofeware ANSYS;(3) It describes about the casing wear remaining strength analysis during casing drilling, including wear experiment research and casing wear and remaining strength analysis;(4) It describes about finite element analysis of casing thread joint. It introduces common thread bearing torque structure and establishes the finite element model of casing thread bearing torque ability.In brief, this thesis combines the drilling engineering actuality to analyze relevant mechanical property of casing string. And it provides technological support of mechanical analysis to further development of casing drilling technology. It provides new theory basis and methods to the research of casing string of casing drilling.更多还原