Structural Integrity Assessment For Ageing Offshore Jacket Platforms

As main equipment for ocean oil development,the structure of offshore platforms are complex,and the cost is high.The design life of offshore platforms is generally not too long.Therefore,since offshore oil drilling was exploited,quite amount of platforms entered the aged service period.And as the main application platform,Jacket Offshore Platform is a platform form which is in more serious aging condition.The paper applies structural integrity assessment system,by building the integrity management system of the jacket platform,to assess structure and state,analyze service level and ultimate bearing capacity and removing for the aging jacket platform,so as to decrease the cost of offshore oil drilling,improve the level of security.The economic efficiency is remarkable.This paper mainly aims for the present situation of serving platforms,combines research and project about the aging platform,and regards aged jacket platform as research object.Under the integrity management system,the paper does related research about service status and retirement for offshore aged platforms.This paper surveys the application field and development of integrity management theory of domestic and overseas to propose the definition and framework process of structural integrity management,and then establish the fine structure model of jacket platform by software of finite element analysis,including the overall model and the local structure of fine model;consider the data of soil and environmental,the analysis of static and dynamic and the stress analysis of key components and evaluation of residual life was carried on;study the characteristics of static nonlinear,the dynamic response and the level of ultimate bearing capacity under the condition of the extreme storm surges;determine the service level and the scheme of maintenance and retire based on the evaluation data of service status;research the general steps of the platform decommissioning disposal and analyze rationally the key technologies in disposal.In order to ensure the safety of the process of retired disposal,the analysis of cutting and lifting strength and stability was carried on in the process of removing by software of finite element analysis.