超短半径水平井柔性钻具设计及力学分析

发布时间：2019-05-21 14:58

【摘要】：面临着我国老油田的开发已经进入中后期的严峻形势,油井产油量严重下跌,如何研究应用新方法挖潜剩余油藏,提高油井产油量,已经成为各大油田迫切需要解决的任务。面对着国内各油田产油量日益下滑的趋势,在老井中采用超短半径开窗侧钻水平井工艺技术开发剩余油技术越来越受到各大油田的青睐,而超短半径开窗侧钻水平井工艺技术的核心就是是否有一套科学合理的柔性钻具设计。柔性钻具的主要部件是导向筛管和柔性钻杆,故导向筛管和柔性钻杆结构设计以及力学分析是否合理直接影响柔性钻具在钻井过程中能否成功进行造斜钻进和水平钻进。为此,本文根据超短半径水平井技术特点,对超短半径水平井柔性钻具进行了结构设计,并进行了力学分析。采用理论分析方法,考虑导向筛管开槽结构,对导向筛管每节长度、竖缝的夹角、竖缝的长度、竖缝宽度和横缝宽五个主要参数进行设计,建立导向筛管强度评价准则,提出最优结构。考虑导向筛管与井壁的接触,以导向筛管和井壁为研究对象,采用梁单元,建立导向筛管和井壁接触非线性有限元模型,并对其进行力学分析,得到导向筛管危险截面载荷;为评价导向筛管强度,取单节导向筛管为研究对象,采用实体单元,建立单节导向筛管局部有限元模型,将整体模型得到的危险截面载荷加到局部模型上,对其进行强度评价,得到开窗点轴向力为40kN,钻进90°导向筛管满足强度要求。考虑柔性钻杆能够通过一定曲率半径的井眼,根据几何关系和强度条件,对单节柔性钻杆的长度、球头柱键的直径、球头连杆和上球座的内径等主要参数进行结构设计。考虑球头柱键与球头连杆凹槽、上球座与球头连杆球头的接触,取单节柔性钻杆为研究对象,采用实体单元建立单节柔性钻杆接触非线性有限元模型,对其进行强度评价,得到造斜段柔性钻杆能承受小于2kN?m的扭矩,水平段柔性钻杆能承受小于40kN的钻压和小于2kN?m的扭矩。
[Abstract]:Facing the severe situation that the development of the old oil fields in China has entered the middle and late stage, the oil production of oil wells has seriously fallen. How to study the application of new methods to tap the remaining oil reservoirs and improve the oil production of oil wells has become an urgent task to be solved in each major oil field. In the face of the declining trend of oil production in domestic oil fields, the development of remaining oil technology by using ultra-short radius windowed sidetracking horizontal well technology in old wells is more and more favored by major oil fields. The core of ultra-short radius sidetracking horizontal well technology is whether there is a set of scientific and reasonable flexible drilling tool design. The main components of flexible drilling tool are guide screen pipe and flexible drill pipe, so whether the structural design and mechanical analysis of guide screen pipe and flexible drill pipe can directly affect whether the flexible drilling tool can successfully carry out oblique drilling and horizontal drilling in the drilling process. Therefore, according to the technical characteristics of ultra-short radius horizontal wells, the structure design and mechanical analysis of flexible drilling tools for ultra-short radius horizontal wells are carried out in this paper. By using the theoretical analysis method and considering the slotted structure of the guide screen tube, five main parameters, namely, the length of each section of the guide screen tube, the angle between the vertical joints, the length of the vertical joints, the width of the vertical joints and the width of the transverse joints, are designed, and the evaluation criteria of the strength of the guide screen tubes are established. The optimal structure is put forward. Considering the contact between the guide screen tube and the shaft wall, the nonlinear finite element model of the guide screen tube and the shaft wall contact is established by using the beam element, and the dangerous section load of the guide screen tube is obtained by mechanical analysis. In order to evaluate the strength of the guide screen tube, taking the single section guide screen tube as the research object, the local finite element model of the single section guide screen tube is established by using the solid element, and the dangerous section load obtained by the whole model is added to the local model, and the strength is evaluated. The axial force of the window opening point is 40kN, and the 90 掳guide screen tube is drilled to meet the strength requirements. Considering that the flexible drill pipe can pass through a hole with a certain curvature radius, according to the geometric relationship and strength conditions, the main parameters such as the length of the single flexible drill pipe, the diameter of the ball head column key, the inner diameter of the ball head connecting rod and the upper ball seat are designed. Considering the contact between the ball head column key and the ball head connecting rod groove, and the contact between the upper ball seat and the ball head connecting rod ball head, the single flexible drill pipe is taken as the research object, and the nonlinear finite element model of the single section flexible drill pipe contact is established by using the solid element, and its strength is evaluated. It is found that the flexible drill pipe in the inclined section can bear the torque less than 2kN?m, and the flexible drill pipe in the horizontal section can bear the drilling pressure less than 40kN and the torque less than 2kN?m.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE92

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