钻杆连接螺纹结构研究

发布时间：2018-04-02 07:24

本文选题：锥螺纹　切入点：圆柱螺纹　出处：《中国地质大学(北京)》2017年硕士论文

【摘要】：在石油钻井与地质岩心钻探施工中,钻杆柱作为钻进最主要的传输部分,承担着传递作用力以及作为钻井泥浆通道等重要作用。实际生产情况表明,钻杆柱的组成单元钻杆作为钻进过程中的主要传力和受力部件,其危险断面往往在连接螺纹处。通过研究螺纹失效的形式和具体部位,对螺纹结构进行优化,一定程度上减小螺纹处的破坏。参照现有的石油钻杆接头螺纹:31/2REG(正规型)和地质岩心钻探接头螺纹:公称口径59的两种螺纹类型,利用SolidWorks软件进行建模,并导入ANSYS Workbench有限元软件进行仿真模拟,分析锥螺纹和圆柱螺纹结构特点。仿真结果表明:两种螺纹具有以下共同点:(1)螺纹应力(应变)集中部位在外螺纹根部至第3圈处。(2)主要失效的形式有根部断裂以及纵向开裂。(3)在外螺纹的起始部位,由于出现应力应变集中,在加工时需要进行切削处理,即厚度小的位置牙高小。两种螺纹的不同处有:(1)在受到扭矩作用下,锥螺纹根部第1、2圈应力集中相对第3圈明显,而圆柱螺纹根部3圈则分布较均匀。(2)在受到同样扭矩的作用下,锥螺纹的台肩处比圆柱螺纹台肩处应力集中程度大。在对两种不同结构的螺纹研究的基础上,对受力响应更灵敏并在有利用前景的平牙底圆柱螺纹进行建模仿真并优化。以最大化的将应力集中转移到牙底所在的台体上为原则,对螺纹的螺距进行优化,进而优化其他参数。优化后的非标准体系圆柱螺纹主要尺寸为:螺距6.5mm、牙型高度1mm、牙型半角7°、外螺纹牙顶宽3.117mm、内螺纹牙顶宽3.127mm、外螺纹大径(内螺纹大径)21mm、外螺纹小径(内螺纹小径)19mm等。通过对优化后螺纹的建模与仿真,优化后的非标准口径的接头螺纹能够降低压力作用下的应力应变28.6%,降低压力及弯矩作用下螺纹的应力应变15.92%,扭矩及压力作用下的应力应变增大约8%。优化后螺纹整体表现较好。
[Abstract]:In oil drilling and geological core drilling, drill string, as the most important transmission part of drilling, plays an important role in transmitting force and acting as drilling mud channel.The actual production shows that the component unit of drill string as the main force transfer and force components in drilling process, the dangerous section of drill string is often located at the connection thread.The structure of thread is optimized by studying the form and position of thread failure to reduce the damage of thread to a certain extent.Referring to the two kinds of thread types of existing oil drill pipe joint thread:: 31 / 2REG (normal type) and geological core drilling joint thread: nominal caliber 59, using SolidWorks software to model the model, and importing ANSYS Workbench finite element software to simulate,The structural characteristics of taper thread and cylindrical thread are analyzed.The simulation results show that the two kinds of threads have the following common points: 1) the stress (strain) concentration part of the thread thread. (2) the main failure forms of the outer thread from the root to the third ring are root fracture and longitudinal cracking. 3) the starting position of the external thread.Due to the stress and strain concentration, cutting is needed in machining, that is, the lower thickness of the tooth is high and small.The difference between the two kinds of threads is: (1) under the action of torque, the stress concentration of the first second ring of the taper thread root is obviously relative to the third circle, while the stress concentration of the cylindrical thread root is more evenly distributed under the action of the same torque.The stress concentration at the shoulder of the tapered thread is greater than that at the shoulder of the cylindrical thread.Based on the research of two kinds of thread with different structure, the stress response is more sensitive and the model simulation and optimization are carried out on the flat bottom cylindrical thread which has the prospect of utilization.Based on the principle of maximum stress concentration transfer to the base of the tooth, the screw pitch of the thread is optimized and other parameters are optimized.The main dimensions of the optimized non-standard cylindrical thread were as follows: pitch 6.5mm, tooth height 1mm, tooth half angle 7 掳, top width of outer thread 3.117mm, top width of inner thread 3.127mm, large diameter of outer thread (internal thread diameter 21mm), outer thread diameter (internal thread diameter 19mm).Through modeling and simulation of optimized thread,The optimized joint thread with non-standard caliber can reduce stress and strain 28.6 under pressure, reduce stress and strain of thread under pressure and bending moment, increase stress and strain by about 8% under torque and pressure.The overall performance of the optimized thread is better.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE921.2

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