深井完井管柱振动特性分析及实验研究

发布时间：2018-02-02 17:41

本文关键词： 完井管柱振动特性固有频率动力响应现场实验　出处：《西安石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：完井管柱是地层流体产出以及地面工作液注入产层的重要通道,流体流速和压力的波动会诱发完井管柱的振动。管柱的受迫振动会造成管柱的疲劳破坏、磨损破坏,甚至在井下断裂,研究完井管柱的振动特性对于确保完井管柱长期安全可靠工作有重大意义。本文首先分析了使完井管柱产生振动的内部因素、外部因素及管柱内部流固耦合机理,使用能量法及达朗伯原理分别建立了管柱横向及纵向振动方程,利用分离变量法及边界条件,求解振动方程并得到了管柱的固有频率。接着,分析了封隔器约束、管柱尺寸、弹性模量、内压对完井管柱固有频率的影响。然后,分析管柱在简谐激励下的动力响应,以管柱结构图及生产工况为分析依据,以响应应力、响应位移、响应加速度为指标,横向对比了完井管柱同一井深不同工况下的振动响应情况,纵向对比了同一工况不同井深处的振动响应情况。最后,根据管柱振动测试器在现场所测得的振动加速度数据,以应力为评价指标分析了管柱在振动较为剧烈工况下的安全性。分析结果表明,完井管柱流固耦合振动固有频率不但与管柱本身的抗弯刚度、质量、尺寸有关,还取决于流体的流速、密度、轴向力、跨距。对管柱施加封隔器约束,考虑内压,增加壁厚、外径、弹性模量、尽可能减小管柱的长度都将有助于增大管柱的固有频率,对抑制完井管柱的振动有积极作用。在本文分析的管柱结构下,管柱系统中段的响应应力、响应速度、响应加速度最大,为整趟管柱中较为危险的部分。此外,在开关井作业时完井管柱的振动相较于其他工况更为剧烈,易发生共振,使管柱产生塑形变形,须引起施工方充分的重视。
[Abstract]:Completion string is an important channel for formation fluid production and surface working fluid injection. The vibration of completion string will be induced by the fluctuation of fluid velocity and pressure. The forced vibration of string will cause fatigue damage of string. It is very important to study the vibration characteristics of the completion string to ensure the safety and reliability of the completion string for a long time. This paper first analyzes the internal factors that cause the vibration of the completion string. The lateral and longitudinal vibration equations of pipe string were established by energy method and Dalmberg principle respectively. The separation variable method and boundary conditions were used. The vibration equation is solved and the natural frequency of the string is obtained. Then, the effects of Packer constraints, string size, elastic modulus and internal pressure on the natural frequency of the completion string are analyzed. The dynamic response of pipe string under simple harmonic excitation is analyzed according to the structure diagram of pipe string and production conditions and the response stress displacement and acceleration are taken as the index. The vibration response of the completion string under the same well depth and the different depth of the well under the same condition is compared horizontally. Finally, the vibration response of different well depths under the same working condition is compared. According to the vibration acceleration data measured by the string vibration tester in the field, the safety of the pipe string under the more intense vibration condition is analyzed with the stress as the evaluation index. The analysis results show that. The natural frequency of fluid-solid coupling vibration of the completion string is not only related to the bending stiffness, mass and size of the string itself, but also depends on the flow velocity, density, axial force and span. Considering the internal pressure, increasing the wall thickness, external diameter, elastic modulus and minimizing the length of the string will help to increase the natural frequency of the string. Under the string structure analyzed in this paper, the response stress, response speed and response acceleration of the middle section of the string system are the most dangerous part of the whole string. Compared with other working conditions, the vibration of the completion string in the switching well is more intense and resonant, which causes the tubing to be shaped and deformed, which should be paid more attention to by the construction side.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE925.3

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