Research On Technology Of Naval Architecture Design Of Semi-Submersible Crane & Accommodation Platform

There are abundant oil and gas resources in Deep Ocean.With the continued growth in energy demand,deepwater oil and gas exploitation has been the focus of many countries,and deepwater marine engineering equipment has been the symbol of comprehensive national power.So improving the deepwater equipment level and accelerating the offshore oil and gas exploitation have been our urgent affairs.As offshore engineering equipment,the deepwater semi-submersible platform is the mainstream equipment in oil and gas exploitation of Deep Ocean.As an important part of high-end manufacturing of offshore engineering equipment,the deepwater semi-submersible crane & accommodation platform integrates various high technologies.It can provide the necessary drilling material conveying,goods storage,offshore installation,staff residence,medical treatment and entertainment facilities for drilling and production platforms.The multi-functionality of deepwater semi-submersible crane & accommodation platform leads to the complexity of its structure and systems,and gives it the characteristics of long term design cycle and high difficulty.During the research and development process,the general arrangement design will be directly related to the merits of the platform,which is the functional foundation of drilling support,offshore installation,supply,living,etc.,so it directly relates to the success of the platform design.The paper is based on the deepwater semi-submersible crane & accommodation platform“OOS Gretha” which is designed by Yantai CIMC Raffles offshore limited with firstly own the proprietary intellectual property rights in china.The paper discussed the key technology of the naval architecture design,researched and summarized optimization technique of general arrangement basing on improving positioning capability and comfort,improved the comprehensive performance of the platform.The paper mainly includes the following aspects:1)Introduced the development process,trends and characteristics of semi-submersible crane & accommodation platform,and discussed the naval architecture design of the asymmetric semi-submersible crane & accommodation unit without bracing.The platform isdesigned with the goal of improving safety and efficiency,with the principle of reasonably arranging the general layout,to achieve reasonable layout of lifting and living equipments,to ensure the convenience of offshore operation.In order to meet the demand of upgrading the platform to be pipe-laying or drilling unit,the main-deck is reserved enough space.Considering the demand of ergonomics,the platform is designed to meet the goal of reside comfort,operation,fire prevention and escape.2)Through studying domestic and foreign technology on the semi-submersible platform,analyzed the integrated design technology and general arrangement of platform.Against the sea conditions of Mexico,Brazil and British North Sea,and based on the asymmetric semi-submersible crane & accommodation unit without bracing,analyzed the main factors such as rules of layout,hydrodynamics,positioning ability,functional module division and verification of orthocenter of semi-submersible crane & accommodation platform in integrated design process.Against the general arrangement of semi-submersible crane &accommodation platform,with the lifting capacity and vital function as the kernel and basic starting point,divided the platform into modules on functional basis,and designed the general arrangement of pontoon,column and deck box of the asymmetric semi-submersible crane &accommodation unit without bracing.It has been found that the designed general arrangement is high-efficiency and feasible,which has certain guiding significance on the following engineering.3)Through comparing and analyzing the stability,weight,exercise performance and other aspects among the platforms with symmetric and asymmetric pontoon,it is proved that the optimized asymmetric structure without bracing can reduce the light weight,improve the stability characteristics in lifting operation,and reduce the towing resistance and benefit small engineering auxiliary vessel shuttling.The reserved moon pool is used for functional refit of J type pipe-laying later.4)Used the statistical energy analysis method to simulate the cabin noise at different engineering stages on the semi-submarine crane & accommodation platform,and compared with NORSOK standard.Optimized the layout of the area with noise out of limits based on the comparison,then verified the new modification with site noise survey.The result of noise survey proved that the noise control and optimized layout were accuracy,which provides a reference for the layout optimization of semi-submersible platform.5)The positioning capability in operation(lifting operation condition,accommodation working condition etc.)of semi-submersible crane & accommodation platform is directly related to the operation safety and function realization.The paper researched on the calculation method of dynamic positioning capacity of semi-submersible crane &accommodation platform,and developed the dynamic positioning capacity analysis.And analyzed the selection and arrangement of thrusters based on the dynamic positioning capacity curve produced from the above research.The paper researches on the layout planning,ship optimization design,vibration and noise control,optimization arrangement of thrusters of deepwater semi-submersible platform.The achievement has significant referential significance on the naval architecture design of the semi-submersible crane & accommodation platform.