Research On Anti-icing Performance Of Marine Riser

As a key component connecting the offshore platform and the submarine pipeline,the riser is the core equipment for oil and gas production.With the continuous development of oil and gas resources in high latitude regions,ice load has gradually become a controlled load.The ice resistance of marine risers is crucial in the ice resistance design of oil and gas production equipment.The force of sea ice load on the structure is greatly affected by the ice velocity effect.Therefore,the determination of the ice load model and the conditions for the occurrence of steady-state vibration are the focus of the research on the ice resistance of marine risers.This paper mainly uses model tests and numerical simulations to study the ice load of vertical flexible structures such as risers,and provides references for the ice-resistant design and safety evaluation of marine risers.The research content of this article includes:1.Clarify the mechanical properties of polar drilling risers.Polar drilling riser is a typical flexible structure,and the interaction mechanism between sea ice and this type of structure is complicated.By comparing the basic characteristics of offshore platforms,wind power foundations and polar drilling risers in the Bohai Sea,the mechanical properties of polar drilling risers have been clarified.To study the ice resistance of offshore risers,it is first necessary to determine the ice load on the offshore risers.2 Study the ice velocity effect of polar drilling risers through model tests.Through model experiments,the ice force mode of a specific polar drilling riser under the action of leveling ice is analyzed under different ice speeds.Analyze ice force models at three ice speeds: fast,medium,and slow,and explore the possible ice speed range when ice shock steady-state vibration occurs.Combined with theoretical calculations,the equivalent length of the time stress field of the polar drilling riser and ice-leveling action is determined.3.Analyze the ice load of the drilling riser through discrete element simulation.Discrete element software Ice DEM is used to study the collision problem of ice floes,statistics the time distribution of ice collisions,and analyze the influence of ice forces of different ice speed,ice thickness,average size and density of ice floes on ice force.At the same time,the ice velocity effect and steady-state vibration range of polar drilling risers with lower horizontal stiffness and lower fundamental frequency at the waterline are analyzed.4.Research the anti-icing performance of the platform cable duct of the wind farm booster station.The response of the structure under the action of static ice force and the steady state vibration of the structure caused by ice is analyzed,and the ice resistance performance of this type of cable duct is evaluated.Finally,the ice accumulation process and analysis methods of the riser group are discussed.