Study On Leveling System Of Deep Water Jacket

With the accelerating trend of economic globalization and modernization,the consumption of fossil energy in every country in the world is increasing day by day,and the amount of resources has become an important factor to measure the development of a country.In recent years,China's oil and gas consumption shows a growing trend.The South China Sea contains a large number of oil and gas resources,most of which are to be exploited in the deep sea.With the development of the 12 th Five-Year Plan,China attaches more importance to the exploitation of oil and gas resources in the deep sea.At present,the jacket leveling technology is mainly based on the traditional operation mode.Special leveling clamping apparatus is used to independently adjust the legs on the four sides of the jacket.After several adjustments,until the level of the jacket platform meets the leveling requirements,the leveling method is inefficient,accurate and difficult to control.In this paper,the deep water jacket leveling system is analyzed and studied,and the problems existing in improving the traditional leveling method are mainly included in the following aspects.The installation process of jacket platform and the overview of clamping apparatus are described.The overall mechanical structure of the leveller and the internal structure and connection form of the main parts are analyzed in detail.According to the friction theory,the upper clamping mechanism is analyzed.According to the material and technical requirements of the main parts of the middle hydraulic cylinder,the structural dimension parameters are calculated and the connection mode of each part is clarified.Considering the dynamic and static characteristics of the hydraulic cylinder,determine the sealing mode between the cylinder block assembly,piston rod assembly and the inner surface of the cylinder and the piston,determine the overall structure of the hydraulic cylinder,and check the main parts.In the aspect of hydraulic system,the load sensitive pump is selected to coordinate with the load sensitive control system consisting of the reversing valve with the pressure compensator in front of the valve to complete the selection of the load sensitive pump and the electro-hydraulic proportional reversing valve.Combined with the environmental and structural characteristics of deepwater jacket platform,this paper proposes the overall design scheme of adopting PLC as the control core,choosing four-point leveling method and "coplanar" leveling strategy.The control scheme can effectively avoid "empty leg" phenomenon.The mathematical modeling of the control object is established,and the transfer function of the control system is deduced.AMESim/Simulink co-simulation method and fuzzy PID control algorithm are used to verify the feasibility and advancement of the leveling control system.From the simulation results,the position accuracy of the system can be controlled below 2mm,which is significantly improved compared with the traditional leveling method.When the system is subject to the changing external load,the leveling accuracy of the system is almost not affected and the robustness is good.The proposed deep water jacket leveling strategy and leveling control algorithm can effectively solve the problems existing in the traditional leveling system,such as low operating efficiency,difficult control of leveling precision and effect,and easy overload of the system.It has certain practical guiding significance to the same type of engineering application.