张宗峰

(1.天津大学 建筑工程学院，天津 300072；2.中石化石油工程设计有限公司，山东 东营 257000)

西非深水海底管道沉降分析

张宗峰1,2

(1.天津大学 建筑工程学院，天津 300072；2.中石化石油工程设计有限公司，山东 东营 257000)

基于西非深海安哥拉32区块KAOMBO油田实际工程，对海底管道沉降进行了理论分析和数值计算，考虑了极浅层土力学参数的不确定性，认为土体不排水抗剪强度对管道沉降的影响不可忽视，随着土体强度的增加，管道沉降量呈指数衰减，当土体强度达到2.0 kPa时，管道沉降量趋于一致。同时考虑了管道安装过程中纵横向摆动对管道沉降的影响，引入了动力系数，考虑管道触泥点处应力集中产生的附加沉降，荷载集中系数随管道弯曲刚度和土壤刚度增加而增加，随铺设张力的增加而减小，并区分“轻”“重”管道进行了沉降分析，结果与几内亚湾和安哥拉海域实际工程和现场实际观测数据相符。

海底管道；重塑土强度；土壤敏感系数；铺设动力放大系数；附加沉降

Abstract:The settlement of subsea pipeline is analyzed theoretically using FEA method,based on Kaombo project in Angola of West Africa,in which soil parameters uncertainties in shallow layer are considered.Undrained shear strength of soil shall not be ignored,as with the increase of soil strength,pipeline settlement is in exponential attenuation.When the strength of soil is higher than 2kPa,the pipeline settlement gradually reaches the same value.Installation amplification factor is introduced in the analysis of additional settlement caused during installation,and subsea pipeline is distinguished as “light” or “heavy” upon effective weight.Load concentration at pipe touch-down point increases the pipe penetration,and the load concentration factor increases with the bending stiffness of the pipeline and the soil stiffness,and decreases with increasing lay tension.Moreover,the experience from the Gulf of Guinea and Angola engineering and the actual observation data prove the reliability of the result.

Keywords:subsea pipeline; remodeled soil strength; soil sensitivity factor; installation amplification factor; additional settlement

近年来，随着越来越多的油气资源在水深超过500 m的深水区获得发现，西非深海石油开发面临前所未有的大好前景。海底油气管道作为深海油气田开发生产系统的主要组成部分，其在位稳定性尤其是高温高压管道的整体稳定一直是研究的热点，分析管道的稳定性，管道的沉降量是一个重要参数[1-4]。20世纪80年代以来，许多国内外科研机构深入研究了海底管道的沉降问题，得到了一些的研究成果。……