【摘要】 针对四川盆地海相地层提出的旋转下套管的技术要求,研究开发了一种新型双台肩高抗扭特殊螺纹接头。该接头克服了普通特殊螺纹接头扭矩台肩厚度增加带来严重应力集中的技术难题,改善了扭矩台肩处的受力,在提高台肩抗扭能力的同时也保证了台肩处应力在材料屈服极限以内。与此同时,利用有限元法优化了锥面/锥面密封结构,使密封更有效。有限元分析和室内全尺寸试验结果表明,这种接头显著改善了接头受力情况,并降低了扭矩台肩处的应力集中,在抗扭强度方面,接头的强度达到了普通API接头的3倍以上,同时,在如此高的扭矩条件下,气密封性能依然可以达到套管内壁屈服压力。更多还原

【Abstract】 In view of top-drive casing running widely used in marine strata in Sichuan Basin, a new double shoulder high torque premium casing connection is designed to meet the requirement of this new technology. Generally, torsion resistance of premium connections is improved by increasing the shoulder thickness, but that will bring serious stress concentration. This paper changes the traditional design idea, improves the torsion resistance and ensures that the maximum stress at the shoulder is lower than the yield strength of the material. At the same time, the cone/cone seal structure is optimized by the FEA method to make the seal more effective. The results of FEA and test show that this connection can significantly reduce the stress concentration at torque shoulder. Its torsional strength is more than three times of that of the ordinary API joint. At the same time, under such a high torque, the gas sealing ability can still reach the yield pressure of the inner wall of the casing.更多还原