深海钻探取样钻杆螺纹接头优化研究

发布时间：2018-06-25 12:19

本文选题：钻杆螺纹接头 + 密封性能　；参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：钻杆是天然气水合物深海钻探取样设备中的主要组成部分,其作用是传递扭矩和保护钻杆内部取样钻具。钻杆通过螺纹接头首尾相连,在取样过程中受到拉、压、弯、扭等载荷作用。由于钻杆螺纹接头截面形式变化较大,同时海底洋流的横向作用,螺纹接头在复合载荷作用下容易产生应力集中,发生断裂失效或密封失效。在此方面,国内外学者对钻杆接头强度与密封性能已经做了大量研究。本文针对深海钻探取样的特殊环境要求,在前人研究基础上,对钻探取样钻杆螺纹接头进行了深入研究,并给出优化后的结构尺寸。首先介绍了国内外钻杆螺纹接头受力的研究方法,并对其解析法进行了整理总结。然后,利用ABAQUS有限元分析软件建立API接头的轴对称有限元模型,分析了接头在上扣、拉伸、压缩以及扭矩作用下的应力分布规律,研究了应力集中部位的应力变化规律。同时研究了螺纹接头的密封机理和密封性能,并对轴向力作用下螺纹接头的密封性能做了研究和总结。最后,针对螺纹接头的应力集中现象,从螺纹扩锥孔尺寸、双台肩结构和应力减轻槽三个方面对结构进行了逐步改进,并得到最佳优化尺寸。通过有限元方法,对改进结构的逐个对比分析表明,这些改进方案均不同程度的改善了螺纹接头的应力分布状况,降低了危险区域的应力集中,同时提高了螺纹接头密封性能。利用前文的研究结果,对改进前后,单、双台肩结构的接头进行抗弯性能研究。通过对接头三维完全模型的有限元分析,得到预紧扭矩和弯矩作用下螺纹接头的应力分布情况。并推导出了,双台肩结构螺纹接头弯矩承载能力的解析计算方法。研究表明双台肩结构有效分担了弯矩作用,减轻了螺纹接头应力集中状况,提高了密封性能,使螺纹接头能更好的适应海底大弯矩要求。
[Abstract]:Drilling pipe is the main part of the sampling equipment for deep sea gas hydrate drilling. Its function is to transfer torque and protect the internal sampling drilling tool of drill pipe. The drill pipe is connected by threaded joints and subjected to tension, compression, bending and torsion during sampling. Due to the great variation of the cross section of the threaded joint of drill pipe and the transverse effect of ocean current on the bottom of the sea, the stress concentration of the threaded joint is easy to occur under the action of composite load, and the failure of fracture or seal occurs. In this respect, domestic and foreign scholars have done a lot of research on the strength and sealing performance of drill pipe joint. In accordance with the special environmental requirements of deep sea drilling sampling, this paper makes a thorough study on the threaded joint of drill pipe for drilling sampling on the basis of previous studies, and gives the optimized structure size. This paper introduces the research methods of drill pipe thread joint at home and abroad, and summarizes its analytical method. Then, the axisymmetric finite element model of API joint is established by using Abaqus finite element analysis software. The stress distribution of the joint under the action of buckle, tension, compression and torque is analyzed, and the stress variation law of the stress concentration is studied. At the same time, the sealing mechanism and sealing performance of thread joint are studied, and the sealing performance of thread joint under axial force is studied and summarized. Finally, aiming at the stress concentration phenomenon of the threaded joint, the structure is improved step by step from three aspects: the size of the screw expansion cone hole, the double shoulder structure and the stress relief groove, and the optimum size is obtained. Through the finite element method, the comparison and analysis of the improved structure show that these improved schemes improve the stress distribution of the threaded joints in varying degrees, reduce the stress concentration in the dangerous areas, and improve the sealing performance of the threaded joints at the same time. The flexural properties of the joints with single, double shoulder structure before and after the improvement are studied by using the previous research results. The stress distribution of threaded joints under the action of preload torque and bending moment is obtained by finite element analysis of 3D complete model of joints. The analytical calculation method of bending moment bearing capacity of thread joint with double shoulder structure is deduced. The research shows that the double shoulder structure can effectively share the bending moment, reduce the stress concentration of the threaded joint, improve the sealing performance, and make the threaded joint better adapt to the requirements of large submarine bending moment.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE951

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