Numerical simulations of soil physicochemistry and aeration influences on the external corrosion and cathodic protection design of buried pipeline steels

被引:52
作者
Gadala, Ibrahim M. [1 ]
Wahab, Magd Abdel [3 ]
Alfantazi, Akram [1 ,2 ]
机构
[1] Univ British Columbia, Dept Mat Engn, 309-6350 Stores Rd, Vancouver, BC V6T 1Z4, Canada
[2] Petr Inst, Dept Chem Engn, Abu Dhabi, U Arab Emirates
[3] Univ Ghent, Lab Soete, Technol Pk,Zwijnaarde 903, B-9000 Ghent, Belgium
关键词
Soil corrosion; Pipeline steel; Oxygen transport; Cathodic protection; Polarization; Finite element method; CONDUCTIVITY; PASSIVATION; DIFFUSION; MOISTURE; BEHAVIOR;
D O I
10.1016/j.matdes.2016.02.089
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Corrosion of oil and gas transmission pipelines is a serious industrial problem with potentially catastrophic environmental and financial consequences. A finite element model of the external corrosion of buried steel pipelines at coating failures is developed here to better predict degradation in different soil and cathodic protection (CP) environments. Synergistic interactions between steady-state temperature, potential, and oxygen concentration profiles in the soil surrounding the pipeline structure are quantified and discussed. Conductivity and oxygen diffusivity of soil conditions are represented as functions of soil matter, air porosity, and volumetric wetness. Theoretical formulations are uniquely merged with corrosion experiments conducted on actual pipeline steel samples, greatly improving simulation results. Overall, drier sand and clay soil structures cause the most corrosion, whereas wetter conditions impede oxygen diffusion and significantly augment hydrogen evolution. Geometric location of the coating breakdown site relative to the ground surface and the CP anode has a particular influence on oxygen concentration profiles and pipeline corrosion. Model convergence is tested with a mesh sensitivity study, and the model's ability in evaluating practical design changes in the CP system is demonstrated. (C) 2016 Elsevier Ltd. All rights reserved.
引用
收藏
页码:287 / 299
页数:13
相关论文
共 46 条
[41]  
Smith C., 2005, COATINGS CORROSION P
[42]   Predicting carbon dioxide corrosion of bare steel under an aqueous boundary layer [J].
Song, FM ;
Kirk, DW ;
Graydon, JW ;
Cormack, DE .
CORROSION, 2004, 60 (08) :736-748
[43]   Quantifying the effects of soil variability on crop growth using apparent soil electrical conductivity measurements [J].
Stadler, Anja ;
Rudolph, Sebastian ;
Kupisch, Moritz ;
Langensiepen, Matthias ;
van der Kruk, Jan ;
Ewert, Frank .
EUROPEAN JOURNAL OF AGRONOMY, 2015, 64 :8-20
[44]  
Tomlinson M, 2015, PILE DESIGN AND CONSTRUCTION PRACTICE, 6TH EDITION, P1
[45]  
Wijk W.V., 1963, Physics of plant environment
[46]   Heat and mass transfer in landfills: Simulation of the pile self-heating and of the soil contamination [J].
Zambra, C. E. ;
Moraga, N. O. .
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 2013, 66 :324-333