Research On Design And Model Test Of DP Thrust System Of Semi-submersible Drilling Platform

As the development of oil exploration in China, traditional mooring system for ship and ocean engineering could not meet new requirements of drilling platform's nomal operation in seas while developing DP system becomes key technology to solve this problem due to its indepedence on depth of water. This thesis focuses on searching for a reasonable method of DP thrust system design and model test for a drilling platform. The external loads due to wind, current and wave are calculated theoretically and measured in model test at scale 1:50, according to which, DP thrust system is designed. Then, a model test for thrust system designed is carried on to validate the method of designing DP thrust system for semi. Furthermore, a method called dynamic time domain simulation is introduced to simulate the performance of drilling platform with DP thruster system.In the thesis, frame and operational principle of DP system are presented, including position-measuring system, thrust system and control system, and so on. In order to acquire more accurate environmental loads which are used to design and analyse DP thrust system for drilling platform, the external loads on the platform are computed in theory and gauged in experiment. With the condition for model test being taken into consideration, a model test is developed. The results from calculation and experiment are compared to make sure that DP thrust system could produce the thrust as designed. Based on the result from numerical calculation and model test, a method called dynamic time domain simulation is refered to simulate the performance of drilling platform with DP system under design condition and South China Sea 1-Year condition. By this way, the security for DP system is verified. All these work provide valuable reference to practical engineering application and technical methodology for DP capability analysis and evaluation as well.