深海水域钻井隔水管力学特性分析

Analysis of mechanics characteristics of deepsea drilling risers

由于深海水域的环境条件比较恶劣,钻井隔水管的受力状况比较复杂,只有通过分析深海水域钻井隔水管力学特性,才能准确判断其强度和稳定性。利用有限元分析方法建立了海浪、海流等复杂海况作用下深水隔水管受力分析计算模型。在力学模型建立过程中,对海浪、海流作用方式进行了简化处理,并考虑了各种工况条件下隔水管受力状态,提出了波浪有效作用深度的确定方法,得出了波浪载荷的有效作用深度与波高、周期都有一定的关系,波高越大,周期越小,作用深度就较深,反之亦然。同时,利用ANSYS软件,分析了不同载荷作用方式下隔水管在不同水深处的应力及变形变化规律,为深水环境条件下隔水管柱强度设计提供了科学依据。

The relatively poor deepsea environmental conditions lead to the complex capacities of the deepsea drilling risers. The strength and stability of the riser can be precisely estimated only by analyzing their mechanics characteristics. Finite element analysis is used to establish a deepsea drilling riser dynamic analysis model under complex marine conditions such as ocean current and wave. During this process, simplified approach to the action modes of ocean current and wave is suggested and it is proposed to ascertain the positive effect of wave by analyzing the forces of riser system under different conditions. It is indicated that the effective depth of wave force is related to the wave height and period, that is, the effective depth of wave force is increasing with increasing wave height and decreasing wave period, and vice versa. In addition, the variation of drilling risers' stresses and strains at different water depth under the influence of various loading modes is analyzed by the means of finite element analysis software ANSYS, providing a scientific basis for the strength design of deepsea drilling riser columns.