Comprehensive Performance Influence Factors Study And Optimal Design Of Semi-submersible Drilling Platform

In the twenty-first century,oil plays supporting role to a country economic lifeline.Oil and gas resources have been exploited in the last half century,large amount of oil and gas resources can not meet the needs of the development of the national economy.Offshore oil production in 2009 accounted for 33% of the world's total oil production,is expected to 2020 the proportion will be raised to 35%.Offshore platform is one of the main equipment for offshore oil and gas development,study on the response characteristics of offshore platform in the marine environment,and design more excellent performance of the semi-submersible drilling platform,has an important significance for the deep-sea oil equipment and marine petroleum machinery,and which development of national economy means are also.The control variable method is used to analyze the platform in frequency domain and time domain,mathematical model and numerical simulation methods are used to study the response of the platform under specific environmental loads;This paper summarized the existing theories and methods of hydrodynamic knowledge and the optimal design idea,to studies the effect of heave plate on the platform;According to the law of conservation of momentum is put forward the water weight method to platform,the heave plate structure is improved to design the vertical configuration of new swing column and full floating box of semi-submersible drilling platform;Through theoretical analysis and numerical simulation results make general argumentation obtain the performance of the new platform.Numerical results show that with the increase of the wave angle from 0 degrees to 90 degrees,the maximum value and the mean value of the platform surge response are gradually decreasing;When the wave angle is 0,30,and 60 degrees,that the mean value of the platform of type 1compared with platform of type 2 is reduced to 0.0151 m,0.0343 m,0.0272 m,and the corresponding reduction ratio is 4.857%,12.98%,and16.28%,respectively;When the wave angle is 0,30,60,and 90 degrees,that the mean value of the swing of the platform of type 1 compared with platform of type 1 is reduced to 0.2527 m,0.1872 m,0.1660 m,0.1204 m,respectively,and the corresponding reduction ratio is larger;When the wave angle is 0,30,60,90,the response of the heave response is smaller;When the wave angle is 0 degrees,the average heave response of the platform of type1 is 0.3263 m,which is reduced by 0.1066 m compared with the type two platform,and it is reduced by about 24.62%;When the wave angle is 30,60,and 90 degrees,the reducing trend is same,and the reduction ratio is 28.03%,27.49% and 25.26%,respectively.When the wave angle is 90 degrees,the response of the platform is thesmallest;In the range of 0 degrees to 60 degrees,the platform has a larger response.When the wave frequency is close to the natural frequency of the platform of rolling response,which reaches the maximum value under different wave angles;21 additional mass components are independent of the 36 additional mass components.The numerical analysis of the optimal design platform shows that the response of the platform 3,4,5,and 6,respectively,is less than that of the mean value of 24.70%,29.65%,36.36%.The results show that the response of yaw and surge response is influenced greatly by the variation of wave angle,the surge response of the platform decreases with the increase of the wave angle,the sway,surge and heave response of the platform is different in different frequency;The heave response is not sensitive to the direction of the wave,but sensitive to the frequency of the wave;Increasing of water area of platform can increasing the incentive force to platform,So that the platform's sway,sway,heave response has increased;It is helpful to improve the safety of the platform by using the number of columns which are less likely to be possible.The increase of the additional mass of the platform will help to improve the overall performance of the platform,but the additional quality can not be improved too large;21 additional mass components in 36 additional mass components are independent;The 4 column is the best design;platform structure design method and new theory are feasible and reasonable,and has important guiding significantly and reference value for the configuration design of semi-submersible drilling platform in seventh.