Research On The Technology Of Subsea Wellhead Oil And Gas Leakage Rescue And The Stability Analysis Of Containment Device

With the rapid development of global economy,the traditional continental oil and gas resources is difficult to meet human demand for energy,so each country devotes more efforts to developing marine oil and gas resources.However,due to the bottom of the sea environment particularity,subsea wellhead equipment and subsea production system leakage accident occurs frequently.Subsea blowout preventer and subsea christmas tree once leakage,not only affect the safety of the underwater oil and gas system,the more will cause marine environment pollution and great economic losses.Therefore,the research on emergency rescue of subsea oil and gas leak is particularly important and it has important implications for the development of seabed resources.This paper has a deep analysis of oil spill emergency measures which happened in the gulf of Mexico and penglai 19-3 oil field.On the basis of the development trends of underwater oil gas facility leakage sealing and rescue transfer technology and research on underwater oil and gas leak emergency rescue transfer technology,it proposes overall rescue transfer plan for the leakage of underwater blowout preventers and christmas tree,lower the control equipment to the leakage facility to collect leaking oil,then through the operation of remote operated vehicle to achieve the connection of the containment device and the transferring device and convey the leakage oil to the tanker on the sea.According to the leak conditions of undersea facility,the structure design of the key part of the overall program containment device is confirmed.The sink steel plate is the basis for the containment device to ensure the containment device work reposefully under the complex circumstance of high oil leakage pressure and ocean currents at the bottom of the sea.On this basis,this paper analyses the simulation of oil-water two phase flow in the containment device to get the flow field transient parameters in order to verify the feasibility of transfer work and provide a basis for the stability analysis.Through the calculation of containment device in clay soil surface,the ultimate bearing capacity of the soil,skin friction,active and passive earth pressure,the important factors which affect the stability of the containment device is determined and analyzed.According to the bearing external water pressure and internal high oil leakage pressure of containment device,design and check the main framework and linear and nonlinear buckling analysis is carried out on the bearing support frame of the containment device at the same time.Considering the containment device with ocean current vortex-induced vibration,the modal analysis of the containment device is given to avoid approaching the wave excitation frequency and vortex frequency.Finally,according to the bear stress state of the device,the analysis of strength and rigidity can ensure the structure has the capability to meet the working condition.