深水钻井工况下隔水管横向振动特性研究

目前，对隔水管的振动研究鲜有涉及深水钻井工况对其横向振动特性的影响。为此，采用牛顿法建立了隔水管横向振动流固耦合模型，利用微分变换法（DTM）对模型进行求解，分析了钻井液排量与密度、张力比、钻柱结构等因素对隔水管横向振动固有频率的影响规律。结果表明，钻井液的存在会减小深水隔水管横向振动固有频率；隔水管横向振动固有频率随钻井液密度的增加而降低，随张力比的增加而增大；钻井液排量和钻柱尺寸对隔水管的横向振动固有频率影响不大。该研究可用于指导深水钻井作业，优化深水钻井工艺参数。

Study of Characteristics of Lateral Vibration of the Riser in Deepwater Drilling Condition

Study of vibration of riser is rarely about lateral vibration of the riser in deepwater drilling condition. We built the fluid-structure interaction model for lateral vibration of the riser using Newton's method, and solve the model using the differential transform method(DTM). We also analyzed the effects of displacement of drilling fluid, fluid density, tension ratio, the riser's structure and other factors on the natural frequency of lateral vibration of risers. The results show that: the presence of drilling fluid will reduce the natural frequency of horizontal vibration of deepwater riser; natural frequency of the lateral vibration of the riser increases when the density of the drilling fluid decreases and when the tension ratio increase; tension ratio is a very serious impact on the natural frequency of the lateral vibration of the riser. The effect of the drilling fluid displacement and drill string size for the lateral vibration of the riser can be neglected under drilling conditions. The study results can be used to guide the operations and to optimize process parameters of deepwater drilling.