| With the offshore gas and oil development constantly proceeded to deeper water, drillingship has become a main equipment of deep water oil and gas exploration. The expensive deepwater drilling ship, which is disadvantage to structural strength because of its large moonpoolopenings, always works in deep sea area in which the ocean environment is very severe.Severe casualties and great property losses will be caused in case of an accident. Therefore，itis extremely significant to make a global hull FEM analysis of the deep water drilling ship.Taking a3000meter deep water drilling ship as an example，the paper calculates andanalyses the wave loads of the different loading condition based on the three dimensionalfrequency domain theory, and assesses the global hull strength of the drilling ship based onthe equivalent design wave method. The main contents are shown as follows：1. The thesis expounds the constructional features and the survey of market of deepwaterdrilling ship. And researchs the basic requirements of structure form, material, structuremember design, and the hull structure strength of the drilling ship.2. The paper describes the design process of the mid-ship transverse sections. When thestructure arrangement is completed, the paper uses the Nauticus software to do rulecalculation for mid-ship transverse section, according to the requirement of the shipowners and the codes.3. The paper uses SESAM software to calculated wave loads of the entire ship based to thethree dimensional frequency domain theory. Researching the transfer function of thedomain loads of mid-ship vertical moment etc.. The result shows that the heading angle ofRAO between drilling ship and general ship is different. The prediction results arecompared with the wave loads based on the IACS requirements, and research shows that itis necessary to calculate the wave loads with direct prediction method.4. The paper does a global hull analysis based on the equivalent design wave method, andcheck the main structure strength according to the DNV rules. The check result shows thatmost structures of the hull satisfy the strength requirements, but the moonpool corner andconstruction of drill platform is heavy-stressed, where should be paid more attentions.5. The paper establishes Fine mesh models for strength check of the moonpool corner. Thecheck result shows that the moonpool field of lower tween deck does not satisfy strengthrequirements, and this paper gives some modification advices for the failed location. |
