Research And Reliability Analysis Of Hydraulic System Of Subsea Control Module

Due to the great development of productivity in the world,the amount of onshore oil and gas exploitation will be difficult to meet the human exploitation,so countries began to pay attention to the exploitation of offshore oil and gas.Subsea production system is a mature offshore oil and gas production system.The subsea control system is an important control part of the production system,and the subsea control module is the control core.There is still a big gap between China and foreign countries in this field.The hydraulic system of subsea control module,as the power driving part of the underwater valve actuator,is an important part that directly affects oil and gas exploitation.Therefore,it is of practical significance to study the domestic hydraulic system of subsea control module.In this paper,according to the technical indicators of the project and the control requirements of the underwater actuator,an overall scheme of the hydraulic system is designed for the subsea control module.The scheme is divided into two parts,high pressure and low pressure,which can be used to control the downhole safety valve and the valve of underwater oil and gas exploitation respectively.Hydraulic system with redundant supply,can compensate seawater pressure,a variety of sensors for production monitoring;Hydraulic components are mostly installed on the integrated valve plate,coMPact layout,higher integration.Aiming at the hydraulic system scheme of subsea control module,the detailed design and simulation analysis are carried out.By analyzing the opening process of the underwater hydraulic actuator,the input flow and pressure of the hydraulic system of the subsea control module are obtained,which can meet the requirements of valve opening.Considering the velocity of metal pipe,the size of each oil connection pipeline is obtained.A capsule accumulator was used and its precharge pressure and volume were determined.The hydraulic system of the subsea control module is simulated by using SimulationX software,and the rationality of the hydraulic system is verified.The reliability of the hydraulic system of the subsea control module is analyzed.The possible failures of important hydraulic components of the system are studied.Based on the fault forms of hydraulic components,the system fault tree was built,and the system reliability was qualitatively analyzed by fault tree method.The logic block diagram of hydraulic system components is established,and the relationship between hydraulic system reliability and working time of subsea control module is calculated,as well as the mean fault-free time of the system.The influence of component faults on system reliability is analyzed,and some key component faults are simulated and analyzed.The hydraulic system experiments are carried out for the subsea control module prototype.It mainly includes the internal hydrostatic pressure test,internal leakage test and the function test of each key component,which verifies the sealing effect,bearing capacity,redundant supply and the function of each component of the subsea control module hydraulic system.