Research On Key Technology Of Vibration And Noise Of Semi-submersible Drilling Unit For The North Sea's

With the national growing demand for oil and gas resources,the governments focus on the ocean for exploitation of oil and gas.Semi-submersible drilling unit is special offshore structure of a wide range usage.It is one of the main equipment for the exploitation of offshore oil and gas resources.Because of the semi-submersible drilling unit with the difficulty technical and high additional value,its design and construction reflect research level on oil and gas equipment of a country in offshore.The Norwegian North Sea requests for higher standard for design and construction of semi-submersible drilling unit.So the standards for the unit serving in Norwegian Shelf represent the world's highest requirements for such a product.The overall design of high comfort and low noise for the unit presents challenges for the bad waves,low temperature and other harsh environment security.This paper discusses the key technology of the noise and vibration controlling and prediction method for the semi-submersible drilling unit based on NORSOK standard.The calculation and the actual sea trial shows the feasibility of the scheme,set up the vibration and noise analysis process of whole unit.This provides the reference for the design and construction of high comfort of semi-submersible unit in subsequent.Firstly,this paper introduces the vibration calculation and evaluation theory of semi-submersible unit,especially the vibration finite element analysis method of the semi-submersible unit.This paper makes free vibration and forced vibration response analysis on the target unit.Do further analysis and evaluation on vibration characteristics of the target unit according to NORSOK S-002 standard.Results show that it meets the specification requirements,and proved that China's first Norway North Sea semi-submersible drilling unit has good vibration characteristics.Secondly,the basic theory of acoustics and NORSOK specification was introduced.Research the acoustic Statistical Energy Analysis(SEA)method and parameters for noise prediction.This paper is based on VA ONE and predicts noise for the whole cabin of the platform combined with statistical energy analysis method.Finally,considering the vibration and noise analysis result,this paper gives someavailable suggestions to the construction of model room,make sure the suitable of material selection,production process and room layout.The result has provided references for the similar construction.Meanwhile,For some cabin noise out of limit which found during the sea trial,this paper puts forward a project about noise& vibration control.The results of test indicate that the design is feasible and valid and can provides valuable reference for practical engineering projects.