基于水平井多级压裂RFID通讯标签多场耦合动力学分析与优选

发布时间：2018-06-15 00:23

本文选题：多场耦合 + 多级压裂　；参考：《西南石油大学》2017年硕士论文

【摘要】：页岩气已成为我国能源发展的一个新方向,也将成为我国未来清洁能源的重要组成部分。水平井多级压裂技术是目前页岩气开发应用最广泛的方式。近几年,可以实现无限级压裂的基于RFID(无线射频识别)智能滑套的水平井多级压裂技术逐渐应用到水平井压裂领域。但是目前该技术依然存在着标签球下移速度变化大导致的井口控制困难及井底RFID标签球通讯效率低的问题。本文以此为背景从以下几个方面开展了详细研究。(1)调研了水平井多级压裂技术,分析了目前应用RFID智能滑套的水平井多级压裂技术良好前景以及存在的部分欠缺;调研了管内流体携载物体运移和多场耦合问题研究现状,针对性地开展大垂深、大温差、大压力变化的耦合作用下管内流体携载物体运移规律的理论及仿真研究。(2)在考虑地层、环空流体、管柱导热情况下,结合流体力学连续性方程、动量守恒方程和能量守恒方程以及传热学中的热传递公式,建立大垂深、大温差、大压力变化的压裂管柱内流体温度场、压力场、速度场、密度场、粘度场耦合作用数学模型,结合四阶龙格-库塔法与MATLAB软件对上述数学模型进行快速求解,得出沿纵向井深的温度场、压力场、速度场、粘度场和密度场的耦合场分布,并研究分析了入口边界条件对耦合场分布的影响及原因。(3)通过Abaqus软件对标签球变形仿真分析方法、COMSOL软件对标签球动力学分析的静态仿真方法,将管内流体耦合场分布结果作为单向耦合边界条件,求解任意时刻标签球受管内流体携载作用的运动状态及其所在位置。(4)结合标签球静态受力仿真与力学模型分析,进行了标签球直径优选研究,结果表明内径76mm油管压裂工艺中选取水平段时直径48mm的标签球较合适;通过COMSOL软件对比研究不同结构标签球尾涡状态,通过FLUENT软件对比研究不同结构标签球运移动画,提出具有更好工作效果的一种高尔夫球型标签球结构,实现水平井多级压裂技术中提高流体携载标签球运移效率及RFID通讯成功率的目标。研究成果为水平井多级压裂施工的精准控制提供理论和技术支撑,降低压裂作业成本,从而为我国页岩气产业的规模化开发和快速发展做出一定的贡献,也可为海底矿物管内输送、潜水艇救援等类似大垂深、大温差、大压力变化条件下管内流体携载物体运移规律的研究提供理论支持。
[Abstract]:Shale gas has become a new direction of energy development in China and will become an important part of clean energy in the future. Horizontal well multistage fracturing is the most widely used method in shale gas development. In recent years, the multi-stage fracturing technology of horizontal wells based on RFID (Radio Frequency Identification) intelligent sliding sleeve has been gradually applied to the field of horizontal well fracturing. However, there are still some problems in the technology, such as the difficulty of wellhead control and the low communication efficiency of bottom hole RFID tag ball due to the change of downshift speed of tag ball. In this paper, the multistage fracturing technology of horizontal wells is investigated from the following aspects: 1) the good prospect of multistage fracturing technology in horizontal wells with RFID intelligent sliding sleeve and some shortcomings are analyzed. In this paper, the current situation of fluid carrying object migration and multi-field coupling in pipe is investigated, and the theoretical and simulation study on the movement law of fluid carrying object in pipe under the coupling action of large vertical depth, large temperature difference and large pressure variation is carried out in consideration of formation. In the case of heat conduction of annular fluid and pipe string, combined with the continuity equation of fluid mechanics, momentum conservation equation and energy conservation equation, as well as the heat transfer formula in heat transfer, the large vertical depth and large temperature difference are established. The fluid temperature field, pressure field, velocity field, density field and viscosity field are coupled with the four-order Runge-Kutta method and MATLAB software. The coupled distribution of temperature field, pressure field, velocity field, viscosity field and density field along the depth of the vertical well is obtained. The influence of the entrance boundary condition on the coupling field distribution and its reason are analyzed. The static simulation method of the dynamic analysis of the tag sphere by using Abaqus software is discussed in this paper, which is used to simulate and analyze the deformation of the tag sphere by using the COMSOL software. The results of fluid coupling field distribution in pipe are taken as unidirectional coupling boundary conditions to solve the moving state and location of the label sphere under the action of fluid loading in the pipe at any time, combining with the static force simulation and mechanical model analysis of the label sphere. The optimum selection of the diameter of the tag ball is carried out, and the results show that the diameter of the 48mm is more suitable in the horizontal section of the inner diameter 76mm tubing fracturing process, and the trailing state of the different structure of the tagged ball is studied by the Comol software. By comparing and studying the different structure tag ball movement animation by fluent software, a golf ball tag ball structure with better working effect is proposed. In horizontal well multistage fracturing technology, the goal is to improve the efficiency of carrying tag ball migration and the success rate of RFID communication. The research results provide theoretical and technical support for the precise control of multistage fracturing operation in horizontal wells, reduce the cost of fracturing operations, and thus contribute to the large-scale development and rapid development of the shale gas industry in China. It can also provide theoretical support for the study of the moving law of fluid carrying objects in submarine under the conditions of large vertical depth, large temperature difference and large pressure variation, such as submersible mineral pipeline transportation, submarine rescue and so on.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE377

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