水平井分段压裂完井管柱及配套工具的研究

发布时间：2018-02-03 09:36

本文关键词： 套管固井分段压裂力学分析设计密封性能冲蚀损坏　出处：《西南石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：低渗透油气藏储量占大港油田总储量的比重越来越大,在当前能源紧张的形势下,开发好低渗透油气藏十分重要。低孔低渗储层的开采大都具有能量不足的特点,单独以水平井提高储层钻遇率和增大泄油面积不能实现经济高效的开发,需要在完井过程中结合分段压裂措施进行增产改造。但是水平井分段压裂是一项世界级难题,其工艺技术难点在于分段压裂工艺方式的选择以及井下分隔工具与实际需求存在较大的差距。因此,急需对分段压裂完井工具进行改进设计、研发和配套集成应用,为非常规油藏的勘探开发提供完井技术支撑和保障。本文通过设计、理论分析、试验设计和计算相结合的方法,研究了水平井套管固井分段压裂工艺技术,国内对于该工艺技术的研究尚处于起步阶段。研究内容主要包括两大模块,分别为水平井套管固井分段压裂管柱的设计及力学分析,以及管柱配套工具的研究。围绕上述两个模块,主要开展了以下工作：对水平井套管固井分段压裂管柱进行了结构设计及受力情况进行分析。依据管柱设计原则,对分段压裂管柱的结构进行设计。研究了刚性压裂管柱入井的几何条件,解决了压裂管柱配套工具的直径或者长度设计不合理而卡在造斜段的问题。分析了压裂管柱下放过程中与井壁的受力情况,给出了压裂管柱的井口拉力、轴向力及摩阻力的计算公式,并进行了工程实例的应用,确定了下放过程中可能遇到的下放困难点。对套管固井分段压裂管柱的配套工具进行了研究,分别给出了各个配套工具的基本结构、工作原理及技术参数,并设计了工具的可靠性试验方案。建立了滑套球座与憋压球密封过程的力学模型。完成了固井滑套通径尺寸及节流压差的计算。研究了套管固井滑套密封性能。完成了内滑套在极端工况情况下的可靠性分析,确定了最佳材料。建立了球座与憋压球的非线性接触力学模型,分析了不同液压工况对球座及憋压球的等效应力及等效应变分布规律的影响,分析了最大应力值、最大应变值、最大弹性形变值及最大塑性形变值随液压的变化规律。研究了球座锥角对球座与球密封性能的影响,从而确定满足压裂施工要求的最合理的球座锥角角度。研究了套管固井滑套冲蚀磨损规律。建立了内滑套的流场模型,研究了流体流动特性与砂粒的冲蚀速率,分析得出冲蚀损坏的主要原因及关键失效位置。研究了受冲蚀磨损程度与压裂液排量、出口压力、含砂量以及砂粒粒径的关系。最后,对冲蚀磨损进行了量化计算,总结出了冲蚀深度与冲蚀时间的关系曲线,计算得出内滑套的安全使用时间。
[Abstract]:Low permeability reservoir reserves account for the proportion of the total reserves of Dagang oil field more and more, in the current situation of energy shortage. It is very important to develop low permeability reservoirs. The exploitation of low porosity and low permeability reservoirs mostly has the characteristic of insufficient energy. It is not possible to achieve economic and efficient development by using horizontal wells alone to improve the drilling rate of reservoirs and increase the oil discharge area. It is necessary to combine fracturing with fracturing to increase production during completion, but the fracturing in horizontal wells is a world-class problem. The technical difficulty lies in the selection of fracturing technology and the gap between the downhole separation tool and the actual demand. Therefore, it is urgent to improve the design of the segmented fracturing completion tool. R & D and supporting integrated application provide well completion technology support and guarantee for exploration and development of unconventional reservoirs. Through the combination of design, theoretical analysis, test design and calculation, the fracturing technology of casing cementing in horizontal wells is studied in this paper. The domestic research on this technology is still in its infancy. The research mainly includes two modules, namely, the design and mechanical analysis of casing cementing fracturing string in horizontal wells. Around the above two modules, mainly carried out the following work: The structural design and stress analysis of casing fracturing string in horizontal well are carried out, according to the principle of pipe string design. The structure of the fracturing string is designed and the geometric conditions of the rigid fracturing string entering the well are studied. This paper solves the problem that the diameter or length of the matching tool for fracturing string is not reasonable and is stuck in the diagonal section. The stress situation of the fracturing string and the wellbore during the down-running process is analyzed, and the well head tension of the fracturing string is given. The formulas of axial force and frictional resistance are calculated, and the application of engineering examples is carried out to determine the difficult points that may be encountered in the process of transfer. The matching tools of casing cementing fracturing string are studied, and the basic structure, working principle and technical parameters of each supporting tool are given. The reliability test scheme of the tool is designed, the mechanical model of the sealing process between the slider ball seat and the pressurized ball is established, and the calculation of the diameter dimension and the throttling pressure difference of the cementing slider sleeve is completed. The sealing performance of casing cementing sliding sleeve is studied. The reliability analysis of inner sliding sleeve under extreme conditions is completed and the best material is determined. The nonlinear contact mechanics model of ball base and pressure ball is established. The influence of different hydraulic conditions on the distribution of equivalent stress and strain of ball pedestal and pressure ball is analyzed, and the maximum stress and strain value are analyzed. The influence of cone angle of ball base on the performance of ball pedestal and ball seal is studied, so as to determine the most reasonable angle of cone angle of ball base to meet the requirements of fracturing operation. The erosion and wear law of casing cementing slider sleeve is studied. The flow field model of inner sliding casing is established, and the fluid flow characteristics and erosion rate of sand particles are studied. The main causes and key failure locations of erosion damage are obtained. The relationship between erosion wear degree and fracturing fluid discharge, outlet pressure, sand content and sand particle size is studied. The quantitative calculation of erosion wear was carried out, and the curve of the relationship between erosion depth and erosion time was summarized, and the safe operation time of inner sliding sleeve was calculated.
【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】：TE357

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