Research For Strength Analysis Of High Pressure Piping System For Semi-submersible Drilling Platform

Semi-submersible drilling platform is important equipment for oil and gas development and the strength analysis and evaluation of high-pressure piping system is also the important guarantee for the drilling operation and drilling safety of the platform.At present,there is no specific requirement and explanation of rules for the analysis method of the high-pressure piping system of the drilling platform.Therefore,it is of great practical significance to study the stress analysis method of high-pressure piping system of semi-submersible drilling platform.This paper mainly studies and summarizes the design loads,the combination of loadcases,evaluation criteria and stress intensification factor of local joint of drilling piping system of semi-submersible platform,and the conclusions obtained have been applied to the actual engineering projects.The main contents of this paper are as follows(1)The theoretical basis of piping stress analysis has been studied and the purpose of piping stress analysis has been clarified here.The classifications of piping stress and failure theory have been introduced.The main contents,checking methods and evaluation criteria of piping stress analysis have been studied.(2)Aiming at the high-pressure piping system of semi-submersible drilling platform,the calculation method of the main loads and the practical application involved in stress analysis has been studied.Based on DNVGL-RP-D101 rule,the calculation load case combination suitable for the analysis of high pressure piping of the semi-submersible drilling platform have been summarized.(3)Taking actual engineering project as an example,the stress analysis and evaluation criteria of typical high pressure piping system of semi-submersible drilling platform has been carried out,including piping strength analysis,fatigue analysis,flange calculation and equipment nozzle analysis.In order to solve the practical engineering problems,modification schemes have been made for the items that do not meet the requirements.(4)By using Finite Element Analysis,the selection of stress intensification factor of elbow and tee has been studied,and the results are compared with those calculated according to the formula in ASME B31.3 code.The problems that should be paid attention to in the process of stress intensification factor calculation(5)The vibration analysis of high pressure piping system has been studied,and the solution to vibration problem in practical engineering project has been put forward.