WANG Guo-tao,ZHU Li-yun,LIU Cen-fan,WANG Zhen-bo,LI An-jun,SHI Jing-yuan.Analysis of Erosion Law of Four-way Pipe in Heavy Oil Thermal Production Wellhead Based on Experiment and CFD Simulation[J],50(8):247-256
Analysis of Erosion Law of Four-way Pipe in Heavy Oil Thermal Production Wellhead Based on Experiment and CFD Simulation
Received:August 10, 2020  Revised:March 01, 2021
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DOI:10.16490/j.cnki.issn.1001-3660.2021.08.023
KeyWord:heavy oil thermal production  sand-containing fluid  four-way pipe  ZG(J)35CrMo  CFD  erosion
                 
AuthorInstitution
WANG Guo-tao China University of Petroleum East China, Qingdao , China
ZHU Li-yun China University of Petroleum East China, Qingdao , China
LIU Cen-fan Key Laboratory of Special Equipment Safety and Energy-saving for State Market Regulation, China Special Equipment Inspection and Research Institute CSEI, Beijing , China
WANG Zhen-bo China University of Petroleum East China, Qingdao , China
LI An-jun China University of Petroleum East China, Qingdao , China
SHI Jing-yuan China University of Petroleum East China, Qingdao , China
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Abstract:
      The work aims to study the problem of erosion and wear on four-way pipe by fluid carrying sand in heavy oil thermal production, so as to define the failure mechanism and characteristics. The metallographic analysis of ZG(J)35CrMo of the damaged four-way pipe was analyzed by metallographic analyzer, and the micro erosion morphology of the four-way pipe was analyzed by scanning electron microscope (SEM). At the same time, the erosion experiment of four-way pipe material ZG(J)35CrMo was carried out by the multiphase flow erosion tester, and the erosion prediction model was established and verified by the single factor erosion experiment. Finally, CFD-DPM-EPM (coupled computational fluid dynamics-discrete particle-erosion) numerical model was established to study the influence of different fluid velocities, particle size and mass flow rate on the erosion law of four-way pipe. The metallographic analysis result shows that the matrix structures of the material were sorbite, ferrite and bainite, and there is slight decarburization on the surface. SEM results show that the inner wall of the failed four-way pipe has obvious sand erosion morphology, and the material has no obvious deterioration and brittle fracture phenomenon. The erosion prediction model is verified by single factor erosion experiment, which proves the accuracy of erosion prediction model constructed by regression analysis method. With the increase of fluid velocity from 5 m/s to 25 m/s, the maximum erosion rate of the four-way tube increased by 16.947 times. When the particle size increased from 0.05 mm to 0.2 mm, the maximum erosion rate of the four-way tube decreased by 2.183 times. However, when the particle size increased from 0.2 mm to 0.4 mm, the maximum erosion rate of the four-way tube increased by 1.382 times. When the mass flow rate increased from 0.15 kg/(m2.s) to 2.4 kg/(m2.s), the maximum erosion rate increased by 16.584 times. The failure of the four-way pipe is mainly due to the erosion of the inner wall of the pipe by particles, and the four-way pipe can not bear the internal pressure after being thinned to a certain thickness. The shoulder of the exit section of the four-way pipe is a high-risk area of erosion, and the maximum erosion rate of the four-way pipe increases exponentially with the increase of the fluid velocity, and with the increase of particle size, the maximum erosion rate decreases first and then increases. When the mass flow rate increases, the maximum erosion rate increases linearly.
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