Petroleum Science >2026, Issue6: 3647-3666 DOI: https://doi.org/10.1016/j.petsci.2026.02.001
Stress characteristics and sealing mechanism of steel-titanium heterogeneous drill pipe joints Open Access
文章信息
作者：Feng Chen, Jia-Qing Liu, Shang-Ying Yang, Su-Na Zhang, Jia-Nan Zhang, Wen-Chang Wang, Qin-Feng Di
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投稿时间：
引用方式：Chen, F., Liu, J.Q., Yang, S.Y., et al., 2026. Stress characteristics and sealing mechanism of steel-titanium heterogeneous drill pipe joints. Petrol. Sci. 23 (6), 3647–3666. https://doi.org/10.1016/j.petsci.2026.02.001.
文章摘要
Titanium alloy drill pipes exhibit promising potential for ultra-deep well drilling due to their high specific strength and superior corrosion resistance. However, the engagement surfaces of the pin and box joints feature distinct material stiffness and surface roughness, which influence both the load bearing characteristics and sealing performance. This study establishes a 3D elastoplastic finite element model for steel-titanium heterogeneous drill pipe joints and analyzes their stress distribution under complex loading conditions. Furthermore, a sealing performance evaluation model based on microscopic leakage mechanisms is proposed, and the sealing performance of single shoulder and double shoulder drill pipe joints is comparatively analyzed. The results indicate that, compared to the NC50 single-shoulder joint, the DS50 double-shoulder joint exhibits a 12.8% improvement in sealing performance under an axial tension of 2500 kN, and a 27.6% improvement under combined loading of 2500 kN axial tension and 8 kN⋅m bending moment. The synergistic action of the primary and secondary shoulders enhances the sealing stability of the drill pipe joint.
关键词
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Drill pipe joints; Steel-titanium heterogeneity; Complex loading; Sealing model; Sealing performance