考虑钻柱作用的深海隔水管柱力学分析

摘要

As an important equipment of offshore oil drilling,the safe use of the risers are directly related to whether the whole drilling operations can be accomplished successfully,even to the whole drilling platform security.At present,researches on riser mechanical analysis were mainly focused on the influences of the ocean environment loads and drilling platform drift,but few on the drill string factors which brought errors to the calculating results.A mechanical model of the risers in deepwater drilling is established,considering the effects of drill string lateral force and axial friction on the risers’lateral deformation and bending moment when tripping up.The model was numerically derived by the finite difference method.Research results show that the lateral de-formation of the risers increases by 7.9% under the influences of the drill string and maximum bending loads appear on the surface of the water.This model provides a theoretical analysis meth-od for the marine riser design,safe use,and deepwater drilling wellhead safety.%隔水管作为海洋石油钻井的重要设备，其安全使用直接关系到整个钻井作业的顺利完成，甚至关系到钻井平台的安全。目前关于隔水管的研究主要集中在海洋环境载荷及钻井平台漂移影响下的隔水管柱力学分析，对于隔水管内部钻柱这一影响因素研究较少，这给计算结果带来了较大误差。考虑起钻过程中钻柱侧向力、轴向摩阻对隔水管横向位移、弯矩的影响，建立了深水钻井时隔水管柱力学模型，用数值差分法进行求解。研究结果表明：考虑钻柱影响下隔水管横向变形影响幅度增加7．9％。靠近水面的位置，隔水管所受弯曲载荷最大。该模型为海洋隔水管设计、安全使用、以及深水钻井井口安全等提供理论分析方法。