| Since 1940s,petroleum products have been widely used in global human production and life,and the demand for crude oil has been increasing steadily.On the basis of land-based oil production and development,human beings began to carry out offshore oil exploration and development.As a safe and reliable offshore oil development equipment,the manufacture of its steel structure of drilling tower pedestal-drilling platform has the characteristics of high quality requirement,great difficulty and high cost.The drilling platform section of semi-submersible drilling platform has the characteristics of complex structure,narrow welding space,large welding quantity and high welding quality requirements.In order to realize the goal of high quality,high precision and high efficiency construction of drilling platform,we first selected the steel plate suitable for the construction of drilling platform according to the strength and welding characteristics of high strength steel plate,and determined that 30mm E36 grade high strength steel was used as the main material for drilling platform construction.Then the welding process parameters suitable for drilling platform high strength steel are explored by experimental method in order to meet the requirements of drilling platform welding strength.Through the study of the welding joint of the drill table structure,it is found that the "-" shaped butt joint of the upper and lower bottom plate of the drilling platform is highly efficient and economical,and the welding quality is good,while for the "T" and"+" shaped angular joints in the drilling platform,carbon dioxide gas shielded welding is the most suitable because of the large number of vertical and back joints.Then different welding current and welding speed are selected for welding of different welding joints.By comparing the weld strength of the sample under different parameters,the optimal welding current and speed parameters are determined,and the drilling platform welding process documents are established according to these parameters.It is also a difficult problem to control the welding deformation of drilling platform.We study the influence of welding groove,gap and welding sequence on the welding deformation of drilling platform,and explore the influence law of these factors on the welding deformation of drilling platform to formulate the process of controlling welding deformation of drilling platform.Because all welds of drilling platform structure are fully melted through(CJP)welds,the amount of welding material filling,welding deformation and welding efficiency are considered comprehensively in the selection of welding groove,and the "X" groove of 50--550 degrees is finally selected as the groove of butt joint and corner joint of drilling platform.Then,according to the difference of weld penetration of different welding equipment,0--2 mm welding gap and 6--10 mm welding root are used for submerged arc automatic welding plate weld,and 0--2 mm welding gap and 0--4 mm welding root are selected for carbon dioxide gas welding.The influence of welding sequence on welding deformation is very obvious,and the welding workload of drilling platform is much larger than that of other ordinary structures,so the amount of heat input is also large.In order to avoid welding deformation caused by excessive local heat input,radiative welding sequence from middle to around should be followed in the welding process of drilling platform,and symmetrical welding should be used where symmetrical welding can be used.Moreover,the welding of the vertical joint should adopt the intermittent welding sequence which extends gradually to both sides to reduce the influence of welding on the deformation of the drilling platform.According to the above research results,the process documents to control the welding deformation are worked out.The goal of welding quality and deformation control of drilling platform can't be realized by using process documents alone.The fifth chapter of this paper pays attention to the process control of drilling platform production,and introduces how to realize the high efficiency and high quality production of drilling platform by reserving margin,according to process construction,personnel management,measurement and inspection,shaping and error correction,etc.,from the beginning of material preparation,by reserving margin,according to process construction,personnel management,measurement and inspection,shaping and error correction,and so on.Moreover,the deformation size,efficiency and quality qualified rate of the drilling platform are compared with the similar products in the previous period,which proves that the research results have made great quality progress and efficiency improvement after the use of the research results.Finally,after a brief review of the research methods and research results in this paper,the research methods and the application prospect of the research technology of semi-submersible drilling platform are properly promoted. |
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