随着深水勘探向超深水发展, 海洋的环境越发恶劣, 隔水管-导管系统易发生屈曲和交变应力疲劳等稳定性问题. 鉴于此, 建立了考虑钻井液上返条件下的隔水管-井口-导管的整体有效轴向力方程, 对系统轴向力进行精确计算; 并将陆地钻井的中性点概念引入海洋钻井, 保证隔水管-导管系统的中性点落在BOP上, 然后综合考虑张力设备能力和立管强度等因素对顶张力进行优选. 该方法分析了钻井液密度与返速对轴向力分布的影响, 提升了系统有效轴向力的计算精度, 能够优选出符合实际工况的顶张力值, 保证了隔水管-导管系统的稳定. 研究结果可为工程实际应用提供参考.%With the exploration of deep water towards ultradeep water, the harsh marine environment could lead to riser-conductor stability issues like buckling and alternating stress failure. The effective axial stress equation of the whole riser-conductor system has been established considering the flow back of drilling fluid. The system axial force has been accurately calculated. Then the neutral point of effective axial stress is introduced in marine drilling to guarantee that the neutral point is located at BOP. The top tension is optimized by considering the factors like ten-sion equipment and the strength of the riser. The proposed method has analyzed the effects of drilling fluid density and return speed on the axial force distribution, thus improving the calculation accuracy of effective axial stress. The top tension could be optimized corresponding to the practical working condition to ensure stability of the riser-conductor system. The results could provide references for engineering application.
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