Research On Key Technology Of Deepwater Gate Valve For Marine Oil And Gas Exploitation

Along with constant improvement of science and technology,especially rapid development of industry,the demand of mankind on oil and gas resources also increases.Oil and gas resources in land and coastal areas have been exploited for many years.The exploitation techniques are already very mature.However,huge demand on oil and gas resources still leads to the oil and gas crisis at different levels worldwide.The shortage of oil and gas resources will have a strong impact on people’s life,and hinder the development of science and technology.Thus,attention has been paid to the sea,which is rich in oil and gas resources.At present,the competition in oil and gas resources has been intensified among countries.The equipment for deepwater oil exploitation in China is basically imported from abroad.Since developed countries in Europe and America blockade the export of new techniques to China,it is extremely urgent for China to independently develop the equipment for deepwater oil exploitation.Valve is an indispensable component for deepwater oil and gas exploitation.It plays an important role in connection and disconnection,and is closely related to the reliability and safety of the entire oil and gas exploitation system.Gate valve is widely applied in deepwater oil and gas exploitation,since it has many distinctive advantages,such as simple structure,convenience in processing and manufacturing,and linear start.Among a variety of valves,gate valve is relatively suitable for deepwater oil and gas exploitation.In view of special working conditions of deepwater oil exploitation,the design of deepwater gate valve is definitely different from ordinary gate valve in many aspects.In the present study,the structure of deepwater gate valve was investigated,designed and optimized in accordance with the structure of existing gate valve and the service conditions of deepwater gate valve.Key parameters of deepwater gate valve were also designed.The high pressure medium inside and outside the body of deepwater gate valve sets a higher demand on its structural strength and tightness.Thus,after the preliminary design of deepwater gate valve,its unit sealing load and fatigue strength were studied,followed by optimized design of findings.Deepwater gate valve is applied in complex working conditions.The load on gate valve includes pressure field and temperature field,which both have impacts on the use of gate valve.The author analyzed the fluid-solid-heat coupling of deepwater gate valve.Its performance in the condition of multi-physical field coupling was studied.Based on the findings,the structure of gate valve was designed and optimized.In deep water,the pressure and velocity of flow field in gate valve is large.The gas-liquid two-phase flow can easily corrode such components as inner wall of valve body,valve seat and gate.Therefore,the internal structures of deepwater gate valve should be resistant to corrosion.The author analyzed the flow of medium in valve body with different opening degrees.Based on the results,optimization methods were proposed,designed and verified.