Study For Key Technologies In The Fast Resuming Production System Of Deepwater Pipeline

With the decrease of petroleum resources on land and in offshore area,submarine oil pipeline is extending to the deepwater.If leak accidents once occur in the deepwater,it might be more difficult to repair urgently,and will cause serious pollution to the environment.Therefore,it is significant to design a fast resuming production system for deep-sea oil and gas pipeline leak.The purpose of the study on key technologies of fast resuming production system of deepwater pipeline is to realize the interim production of oil and gas in short time.Carrying on this research has significant meanings for breaking the overseas technical monopoly and improving the technology of deepwater operation in our country.Based on working environment and technical requirements for the operation of plugging the damaged pipeline,this article proposes a system for fast resuming production of damaged pipeline;completes the development of core part of the system – internal plug test prototype for deepwater pipeline,and verifies its essential functions through anchor seal test,barochamber pressure-bearing test and ocean test on the plug,and puts forward the improvement scheme in combination with technical requirements for fast resuming production system.The article also designs the mechanical locking mechanism with respect to possible risk of oil leakage and pressure drop in hydraulic pressure retaining system,and determined the relationship between its sprocket shape and number and the acting stress and strain as well as its geometrical parameters through mechanic analysis of engaged locking sprocket.As per the functional requirements of the plug in the resuming production system,the distribution rule of variable-diameter pipeline flow field,and the requirements for minimum outer diameter of guide sleeve in plug installation,the article improves and designs the structure of guide sleeve;establishes the mathematical model of the in/out port flow field of the fast resuming production system,and conducts the simulation analysis,showing that application of the improved guide sleeve scheme to the fast resuming production system may obviously reduce the port oil energy loss and the port fluid resistance.In combination with the said improvement scheme and technical requirements for the operation,the article designs the fast resuming production system,determines the system installation scheme,and analyzes the risks involved in system installation and operation.