超深井固井中套管受力研究

发布时间：2018-07-11 17:54

本文选题：超深井 + 固井　；参考：《西南石油大学》2015年硕士论文

【摘要】：本文属于中石油川庆钻探井下作业公司“井下工具管柱力学分析及应用软件研究”项目的部分研究内容。随着超深井越来越多,且超深井具有的管柱长、悬重大、压力高、流动段长的特点。使得套管在浅层井中一些不存在的安全性问题和失效问题不断增加,影响超深井固井安全、经济施工。目前主要采取全井段固井和尾管固井两种方式。通过测量仪器或直接实验的方法来直接判断超深井固井管柱安全性问题很困难,目前最有效的途径是通过不同工况下固井管柱受力特点,建立准确的力学模型和数学模型,应用软件模拟计算成为最有效的方法和手段。本文通过对国内外大量的文献调研、收集和阅读,分析了该领域国内外的研究现状,同时讨论了目前超深井固井管柱力学安全性评价存在的问题,提出了本文主要研究内容和研究思路流程。其主要成果和研究内容如下： (1)完井管柱长、“U”型管效应明显、流速不稳定等特点对超深井固井管柱受力影响明显。综合考虑管柱重力、各种摩擦力、内外流体压力、井眼轨迹、“U”型管效应等因素,建立了直井全井段和尾管段三维管柱力学微分方程。 (2)建立了“U”型管效应下流体流速计算模型,并根据冲击动力原理,得出了超深井固井中流速变化是引起管柱振动的主要原因,建立了流速改变下管柱冲击动载荷力学—数学模型,为管柱安全评价提供了更接近实际工况的动载荷计算公式。 (3)建立了固井过程中不同泵压、排量,不同固井液密度等固井参数下,管柱动态摩阻效应受力计算模型,提出了固井参数对管柱安全性的评价方法。 (4)根据建立的固井管柱各种工况的力学—数学模型、固井过程中的流体动力学数学模型,编写了固井管柱力学分析软件,该软件包含了各种管柱的力学强度数据库、固井工具库,为固井管柱力学强度计算、安全性评价提供简便、可靠的方法和手段。
[Abstract]:This paper is a part of the project of "Mechanics Analysis and Application Software Research of downhole tool string" of CNPC Chuanqing drilling Company. With more and more ultra-deep wells, and ultra-deep wells have the characteristics of long string, heavy hanging, high pressure and long flow section. The safety and failure problems of casing in shallow wells are increasing, which affects the cementing safety and economic operation of ultra-deep wells. At present, it mainly adopts two kinds of methods: the whole well section cementing and the tail pipe cementing. It is difficult to determine directly the safety of cementing string in ultra-deep wells by measuring instruments or direct experiments. At present, the most effective way is to establish an accurate mechanical model and mathematical model through the mechanical characteristics of cementing string under different working conditions. The application software simulation calculation becomes the most effective method and the method. Based on a large number of literatures collected and read at home and abroad, this paper analyzes the present research situation in this field, and discusses the problems existing in the evaluation of the mechanical safety of ultra-deep well cementing string at present. The main research content and research thought flow are put forward in this paper. The main achievements and research contents are as follows: (1) the characteristics of completion string length, "U" pipe effect and unstable velocity have obvious influence on cementing string force in ultra-deep wells. Factors such as string gravity, various friction forces, internal and external fluid pressure, wellbore trajectory, "U" tube effect, etc. In this paper, the differential equations of three-dimensional pipe string mechanics are established. (2) the calculation model of fluid velocity under the effect of "U" tube is established, and according to the principle of impact force, It is concluded that the variation of velocity in ultra-deep well cementing is the main cause of string vibration, and the mechanical-mathematical model of string impact dynamic load under the change of velocity is established. The calculation formula of dynamic load is provided for string safety evaluation. (3) the calculation model of dynamic friction effect of tubing string under different cementing parameters, such as pump pressure, displacement and cementing fluid density, is established. The evaluation method of cementing parameters to string safety is put forward. (4) according to the established mechanical-mathematical model of cementing string and the fluid dynamics mathematical model in cementing process, the mechanics analysis software of cementing string is compiled. The software includes the mechanical strength database and cementing tool database of various string. It provides a simple and reliable method and means for calculating the mechanical strength and evaluating the safety of cementing string.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE256

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