深水钻井中隔水管底部转角及载荷变化规律研究

摘要

A finite element model is established by ANSYS 8.0 to imitate the force condition of riser in order to analyze the influences of top tension and boat drift on riser stability in different wind conditions.This research shows that the load has a linear relation with the boat drift and top tension, the greater the drift, the more the increasing range.However, the corner of bottom ball demonstrates a decreasing model as "fast followed by slow" due to increasing top tension.This research plays a role in safety of sub-sea wellhead in deep-water drilling.%通过有限单元法建立隔水管模型,分析了三级风、八级风——两种不同风力条件下,顶部张力比和船体偏移率对隔水管稳定性的影响.计算结果表明:隔水管底部横向载荷随张力比和偏移率呈线性变化.在张力比增加的过程中,船体的偏移率越大,横向载荷的增加幅度也越大.隔水管底部转角随偏移率的增加呈线性增长,但随着张力比的提高会迅速降低,然后趋于稳定.在保证张力比的前提下,风力的增加对底部转角和载荷影响极为有限.自然条件下,提高张力比是维持隔水管稳定性的有效手段.本研究对分析深水钻井平台的海底井口稳定性有一定指导意义.