Research On Design And Testing Of GLCC Subsea Separator

Subsea separator is one of the key equipment to solve the problems of offshore oil exploitation,separated phase transportation and accurate measurement.The effeciency of subsea separation is directly linked to the oil and gas separation rate in the process of production.In this paper,the overall scheme,main dimension calculation and structure analysis of GLCC subsea separator are studied,and the subsea control system is studied,and the separator level control experiment and system structure experiment are completed.A prototype of GLCC subsea separator suitable for 2000 m subsea was developed.According to the design requirements of subsea separation,the overall design of the subsea separator is carried out.The separation type of the subsea separator is selected as the GLCC subsea separator,and the separator structure design scheme and process control scheme are proposed.On this basis,the mechanical structure of the subsea separator is designed,including: the calculation of the main dimension of the separator,and modeling the principle prototype of the subsea separator,using ANSYS software to conduct the finite element analysis of the prototype.Under the external pressure load of 20 MPa,the allowable external pressure is 121.6Mpa;under the external pressure load of50 MPa,the ultimate load of mechanical plastic deformation failure is 45 MPa.The prototype design is preliminarily checked and confirmed safely.This paper analyzes the status of the subsea control system of the subsea separator abroad,and propose the design requirements for the control system of the subsea separator.Completed the overall scheme design,including: the design of electro-hydraulic control system and the design of liquid level and pressure control system,and gain the optimal design scheme.This paper studies the testing technology principle of the prototype of subsea separator,compares different measurement methods,determines the double differential pressure level transmitter to measure the liquid level in the separator,tests the response performance of the pump and the control performance with the liquid level change,and tests the separation performance of oil,gas and water by obtaining the liquid in gas and gas in liquid.Finally,the principle prototype of subsea separator is tested to meet the performance requirements.Hyperbaric chamber experiment is also carried out on the dangerous parts obtained from finite element analysis to verify the structural strength,stability,sealing and the failure mode of the separator under external pressure environment.The stress and strain data of the key structural parts of the separator are obtained.Then,the experimental results in the hyperbaric chamber are compared with the results of the finite element software analysis,and the damage pressure of the principle prototype of the separator in the hyperbaric chamber is obtained as 40.5Mpa.The results show that the strength and stability of the subsea separator meet the design requirements.