井下作业管柱轴向变形的理论计算及应用研究

发布时间：2018-03-10 17:57

本文选题：管柱受力　切入点：管柱变形　出处：《西安石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着石油需求量的增加和钻探开发技术的不断发展,分段压裂、分层注水及高温高压井开采等井下作业的应用也日益广泛,在这些作业过程中,受管柱自重、温度和压力等因素的影响,管柱在井下会发生轴向变形,如果轴向变形较大将引起作业管柱下入深度不准、封隔器坐封位置偏离目的层、封隔器脱封、管柱断脱及管柱螺旋屈曲等井下事故。长期以来,井下管柱深度主要通过人工地面测量,同时配合电磁测井曲线来校正管柱下入深度及封隔器坐封的准确位置。测磁定位曲线影响因素多、曲线解释困难、作业工作量大、占用生产时间长、成本较高,特别是测试解释数据和人工测量数据相差较大时难以给出解释,准确度不高。而且,磁定位未能考虑电缆的伸长及坐封、压裂过程管柱的轴向变形。因此,准确计算作业过程中不同因素影响下管柱的轴向变形量,对准确定位作业层位、评价井下作业管柱的安全性、合理选择生产作业参数、减少井下作业事故的发生等具有重要意义。本文在前人的研究基础上,通过大量文献调研。首先,综合分析了影响井下作业管柱轴向变形的因素,包括重力效应、浮力效应、温度效应、活塞效应、膨胀效应、摩阻效应和屈曲效应等基本效应的影响;井眼轨迹的影响;封隔器的影响;不同管柱结构类型的影响及不同作业工况的影响。并结合弹塑性力学,利用划分微元后叠加的方法,建立了单一因素影响下作业管柱轴向变形的理论计算模型。其次,通过对管柱微元体受力分析,结合管柱微元体静力平衡方程和物理方程推导出管柱变形的微分方程,通过对微分方程的无因次化,推导出三维弯曲井眼中作业管柱轴向变形的理论计算模型。再次,以水平井分段压裂和分层注水两种井下作业为例,详细分析不同作业工况对管柱轴向变形的影响,建立了不同作业工况下各因素综合影响下管柱轴向变形的理论计算模型,并对计算结果的应用进行了详细分析。最后,以陈平5-2井为例进行了实例计算,计算结果与国际上较为认可的Landmark软件进行了对比,对比验证结果显示计算较准确可靠,根据计算结果可准确的进行井下作业定位、校核作业管柱强度及确定伸缩补偿距等。
[Abstract]:With the increasing demand for oil and the continuous development of drilling and development technology, the application of sublevel fracturing, stratified water injection and high temperature and high pressure well mining is increasingly widespread. Under the influence of temperature and pressure, the pipe string will produce axial deformation. If the axial deformation is large, the depth of the operating string will not be correct, the Packer setting position deviates from the destination layer, and the Packer will be unsealed. For a long time, the depth of pipe string is mainly measured by artificial surface. At the same time, the electromagnetic logging curve is used to correct the entry depth of the string and the accurate position of the Packer seal. There are many factors affecting the magnetic location curve, the interpretation of the curve is difficult, the workload of the operation is large, the production time is long, and the cost is high. Especially when the data of test interpretation and manual measurement are quite different, it is difficult to explain, and the accuracy is not high. Moreover, the magnetic positioning fails to take into account the cable elongation and seal, and the axial deformation of pipe string during fracturing. The axial deformation of pipe string affected by different factors in the process of operation is accurately calculated, and the safety of downhole working string is evaluated, and the production operation parameters are reasonably selected for accurately locating the working layer, evaluating the safety of the downhole working string, and selecting reasonable operating parameters. It is of great significance to reduce the occurrence of underground working accidents. Based on the previous research and a large number of literatures, this paper analyzes comprehensively the factors that affect the axial deformation of underground working string, including gravity effect, buoyancy effect, and so on. The effects of temperature effect, piston effect, expansion effect, friction effect and buckling effect, well trajectory effect, Packer effect, etc. Combined with elastic-plastic mechanics, the theoretical calculation model of the axial deformation of the working string under the influence of single factor is established by using the method of dividing the micro-element after superposition and combining with the elastic-plastic mechanics. By analyzing the force of the tube-column micro-element, combining the static equilibrium equation and physical equation of the tube-string micro-element body, the differential equation of pipe string deformation is derived, and the dimensionless differential equation is obtained. The theoretical calculation model of axial deformation of pipe string in three dimensional curved hole is derived. Thirdly, the influence of different working conditions on axial deformation of pipe string is analyzed in detail, taking two downhole operations of horizontal well fracturing and stratified water injection as examples. The theoretical calculation model of pipe string axial deformation under the influence of various factors under different working conditions is established, and the application of the calculation results is analyzed in detail. Finally, taking Chen Ping 5-2 well as an example, the calculation is carried out. The calculation results are compared with the internationally accepted Landmark software. The results show that the calculation is accurate and reliable. According to the calculation results, the downhole operation location can be accurately carried out, the working string strength can be checked and the telescopic compensation distance can be determined.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE931.2

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