钻柱对隔水管固有频率的影响分析

摘要

隔水管作为海洋石油钻井的重要设备，其安全使用不仅直接关系到整个钻井作业是否顺利完成，而且关系到钻井平台的安全。目前关于隔水管固有频率的研究主要集中在海水质量、隔水管尺寸、顶部张力等因素对隔水管固有频率的影响，但尚未看到钻柱对隔水管固有频率的影响研究。因为隔水管在海水中的运动属于大位移、小变形，内部钻柱随着隔水管一起运动。分析钻柱质量和截面尺寸对隔水导管固有频率的影响。研究结果表明，忽略钻柱质量对隔水管固有频率产生较大误差，最大相对误差约为6．2％。该研究结果为钻井隔水管的设计、安全使用提供一定参考作用。%As an important equipment of offshore oil drilling, the safe use of the marine risers are not only related to the suc-cess of whole drilling operations, but also related to the security of drilling platform.At present, researches on the natural fre-quency of the riser are mainly concentrated at the influences of the oceanic mass, the riser size and the top tension to the natu-ral frequency of the marine riser, yet there isn′t research on the influence of drill string on naturalfrequency of marine riser. Because the movement of marine riser belongs to a large displacement and small deformationin the sea, the drilling moves company with the riser, the influences of drill string quality and its sectional dimension on the natural frequency of the riser are analyzed.The results show that regardless ofthe drill string quality, the relative error that is produced on the first five order of the marine riser's natural frequency is about 6.2%.This study provides the theoretical analysis basisfor the design,safety use of the marine riser, as well as the safety of deepwaterdrilling wellhead.