HJJ900/64-T型海洋超深井井架可靠性分析

HJJ900/64-T型海洋井架是为满足12000 m钻深的自升式钻井平台超深井钻井而研制。该井架设计为满足4单根组成一立根结构的井架高度,比传统的3单根井架至少增加了10 m的高度,达到了64 m。为使该井架满足在恶劣的海洋环境下的使用要求,对井架主体结构进行了可靠性分析。使用有限元分析软件ANSYS对HJJ900/64-T型超深井井架建立了完整的井架有限元模型,根据井架的设计使用条件及自存环境条件,对井架工作工况、风暴自存工况、拖航工况及在顶驱转动、风振、波浪等外部载荷激励时进行了模态分析。分析结果表明,井架在工作工况、风暴自存工况、拖航工况下结构强度及刚度都能满足设计和使用要求,而在拖航工况下受到波浪载荷激励时有可能产生共振。因此可根据共振产生的阵型特性对该井架的局部结构做加强处理,使之更加安全可靠。

Reliability Analysis of the HJJ900/64-T Type Offshore Derrick for Ultra-deep Wells

The HJJ900/64-T offshore derrick is developed for the 12000 m jack-up drilling platform for ultra-deep well drilling.The derrick is designed to have the capacity of 4-joint stand with a height of 64 m.To make the derrick meet the requirements in harsh marine environment,the main structure of the derrick is analyzed for reliability.The finite element analysis software ANSYS is used to build a complete finite element model for the HJJ900/64-T ultra-deep well derrick.According to the derrick design conditions and the surviving environment conditions,the modal analyses are carried out under derrick working condition,storm surviving condition,towage condition and external load excitation such as top drive rotation,wind vibration and wave.Through analyses,it is found that the structural strength and stiffness of the derrick can meet the design and application requirements under working condition,storm surviving condition,and towing condition.Resonance may occur when excited by wave loads under towing condition.Local structure of the derrick could be strengthened according to the formation characteristics generated by resonance to make it safe and reliable.