In this work, X-ray diffraction and Mössbauer spectroscopy techniques were used to characterise and carry out a comparison of the corrosion products obtained during the pigging activities in two sour-hydrocarbon-transporting pipelines located in the Gulf of Mexico: the first one being a gas pipeline and the other one a crude oil pipeline. The results indicate that for these specific conditions, there are differences between the corrosion products formed in each pipeline. Iron sulphides and oxides were the main corrosion products and their presence is directly related to the operating conditions prevailing in the pipelines as well as to the hydrocarbon quality. As for the sour gas pipeline, higher concentrations of greigite and pyrite were observed, whereas more proportions of magnetite, mackinawite and marcasite were found in the sour crude oil pipeline. The most important parameters in the formation of the different types of corrosion products are the water content, hydrogen sulphide concentration and oxygen presence in the system.
KochH.BrongersP. H.ThompsonG.VirmaniO. and PayerJ. H.: ‘Corrosion cost and preventive strategies in the United Stated’, NACE international. Publication No. FHWA-RD-01-156, 2002. Available from: http://www.nace.org/uploadedFiles/Publications/ccsupp.pdf.
SmithG.: ‘ Utility pigs and applications to North slope pipelines’, Maintenance pigging of pipelines conference. Draft Conference Proceedings Report Anchorage. 2006. Alaska.
4.
NRF-030-PEMEX-2009 (Rev:0): ‘Diseño, Construcción, Inspección y Mantenimiento de Ductos Terrestres para Transporte y Recolección de Hidrocarburos’, Comité de Normalización de Petróleos Mexicanos y Organismos Subsidiarios. 1-104.
5.
WyldeandJ. and SlayerL.: ‘Development, testing and field application of a heavy oil pipeline cleaning chemical: a cradle to grave case history’, SPE.20091196881–14.
6.
TakahashiY.MatsubaraE.SuzukiS.OkamotoY.KomatsuT.KonishiH.MizukiJ. and WasedaY.: ‘In-situ X-ray diffraction of corrosion products formed on iron surfaces’, Mater. Trans.200546, (3), 637–642. doi: 10.2320/matertrans.46.637
7.
LaurettaM.DuffóG.FarinaS.SaragoviC. and RamosC.: ‘Caracterización de Productos de corrosión de un acero al carbono mediante Espectroscopia de Mossbauer’, Congreso SAM/CONAMET, 2007.
8.
CookC.: ‘Application of Mössbauer spectroscopy to the study of corrosion’, Hyperfine Interact.200415361–82. doi: 10.1023/B:HYPE.0000024714.84742.fd
9.
ElbridgeJ. and HoffmanW.: ‘A Mössbauer spectroscopy study of the potential dependence of the passivated iron films’, J. Electrochem Soc.1989136955–960. doi: 10.1149/1.2096893
10.
ASTM D 4006-11: ‘Standard test method for water in crude oil by distillation’.
11.
ASTM C 613-14: ‘Standard test method for constituent content of composite prepreg by Soxhlet Extraction’.
12.
MAUD Program, materials analysis using diffraction by L Luttrotti, Version: 2.058 (February 2007). Available from: http://www.ing.unitn.it/maud.
FangH.YoungD. and NesicS.: ‘Corrosion of mild steel in the presence of elemental sulfur’, Paper No. 08637. NACE 2008 Corrosion Conference and Expo.
15.
PackD. J.ParksD. W. and ChesnoyA. B.: ‘Gas pipeline preferential site selection occurrence for elemental sulphur & other particle matter formation & deposition’, J. of Pet. Sci. and Eng.201294-9512–18. doi: 10.1016/j.petrol.2012.06.022
16.
SantosJ. P. L.LobatoA. K. C. L.MoraesC. and SantosL. C. L.: ‘Influence of natural gas composition on the formation and deposition of elemental sulfur in pipelines’, Braz. J. Pet. Gas.201592.
17.
BojesJ.LerbscherJ.WamburiW. and DilleyC.: ‘Elemental sulfur in 3-phase sour gas systems — is condensate really your ally?’, NACE, Northern Area Western Conference.201015–18.
18.
YaakobN.SingerM. and YoungD.: ‘Elemental sulfur corrosion of carbon steel in the presence of sulfur solvent and monoethylene glicol’, NACE International, Corrosion 2015 Conference and Expo. Paper No. 5930.
19.
TaylorP.RummeryT. E and OwenD. G.: ‘On the conversion of mackinawite to greigite’, J. Inorg. Nucl. Chem.1979a 41595–596. doi: 10.1016/0022-1902(79)80454-6
20.
Osseo-AsareK. and WeiD.: ‘Semiconductor Electrochemistry of Coal Pyrite’, Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, Technical Progress Report, January–March 1993.
21.
SmithS. N.PachecoJ. L.: ‘Prediction of corrosion in slightly sour environments’, Paper 02241, NACE Corrosion Conference2002.
22.
LennieA. R.RedfernS. A. T.ChampnessP. E.StoddartC. P.SchofieldP. F. and VaughanD. J.: ‘Transformation of mackinawite to greigite: an in situ x-ray powder diffraction and transmission electron microscope study’, Amer. Mineral.199782302–309. doi: 10.2138/am-1997-3-408
23.
TaylorP.RummeryT. E. and OwenD. G.: ‘Reactions of iron monosulfide solids with aqueous hydrogen sulfide up to 160°C,’ J. Inorg. Nucl. Chem.197941, (12), 1683–1687. doi: 10.1016/0022-1902(79)80106-2
24.
RickardD. and LutherG. W.III: ‘Kinetics of pyrite formation by the H2S oxidation of iron (II) monosulfide in aqueous solutions between 25 and 125 °C, the mechanism’, Geochim. Cosmochim. Acta.199761135–147. doi: 10.1016/S0016-7037(96)00322-5
25.
BernerR. A.: ‘Sedimentary pyrite formation’, Am. J. Sci.19702681–23. doi: 10.2475/ajs.268.1.1
26.
RickardD. and MorseJ. W.: Mar. Chem.200597141–197. doi: 10.1016/j.marchem.2005.08.004
27.
SunW.: ‘ Kinetics of iron carbonate and iron sulfide scale formation in CO2/H2S corrosion’, PhD Theses, The Russ College of Engineering and Technology of Ohio University, 2006.
28.
HungerS. and BenningL. G.: ‘Greigite: a true intermediate on the polysulfide pathway to pyrite’, Geochem. Trans.200781. doi: 10.1186/1467-4866-8-1
29.
WilkinR. T. and BarnesH. L.: ‘Pyrite formation by reactions of iron monosulfides with dissolved inorganic and organic sulfur species’, Geochim. Cosmochim. Acta1996604167–4179. doi: 10.1016/S0016-7037(97)81466-4
30.
BenningL. G.WilkinR. T. and BarnesH. L.: ‘Reaction pathways in the FeS system below 100 °C’, Chem. Geol.200016725–51. doi: 10.1016/S0009-2541(99)00198-9
31.
BernerR. A.: ‘Thermodynamic stability of sedimentary iron sulfides’, Am. J. Sci.1967265, (9), 773–785. doi: 10.2475/ajs.265.9.773
32.
SmithS. N. and PachecoJ. L.: ‘Prediction of corrosion in slightly sour environment’, Corrosion 2002, Paper No. 02241, Nace International, Houston Texas, 2002.
33.
SchieberJ.: ‘Oxidation of detrital pyrite as a cause for Marcasite Formation in marine lag deposits from the Devonian of the eastern US’, Deep-Sea Res. II.2007541312–1326. doi: 10.1016/j.dsr2.2007.04.005
34.
SchoonenM. A. A. and BarnesH. L.: ‘Reactions forming pyrite and marcasite from solution: I. Nucleation of FeS2 below 100 °C,’ Geochim. Cosmochim. Acta.199155, (6), 1495–1504. doi: 10.1016/0016-7037(91)90122-L
35.
SridharN.DunnD. S.AnderkoA. M.LenckaM. M. and SchuttH. U.: ‘Effects of water and gas compositions on the internal corrosion of gas pipelines-modeling and experimental studies’, Corrosion200157, (3), 221–235. doi: 10.5006/1.3290347
36.
LyleF. F.: ‘Carbon dioxide/hydrogen sulfide corrosion under wet low-flow gas pipeline conditions in the presence of bicarbonate, chloride and oxygen’, PRCI Final Report PR-15-9313, 1997.
37.
Winston RevieR.: ‘ Oil and gas pipelines integrity and safety handbook ’, 2015USAWiley426–428.
38.
Abdelmounam SherikM.: ‘BLACK POWDER—1: Study examines sources, makeup in dry gas systems’, Based on presentation to NACE Corrosion 2008 Conference, New Orleans, La., Mar., 2008, 16-20.
39.
JoshiS.VenkateswaranG.VenkateswarluK. S. and RaoK. AP.: ‘Stimulated decomposition of Fe(OH)2 in the presence of AVT chemicals and metallic surfaces—relevance to low temperature feed water line corrosion’, Corrosion199349, (4), 300–309. doi: 10.5006/1.3316053
40.
DavisB. R. and CalabrettaD.: ‘Thermodynamic analysis of formation of black powder in sales gas pipelines’, Saudi Aramco Report No. 6510217086, 2007.
41.
LennieA. R.RedfernS. A. T.ChampnessP. E.StoddartC. P.SchofieldP. F. and VaughanD. J.: Am. Mineral.199782302. doi: 10.2138/am-1997-3-408
42.
BenningL. G.WilkinR. T. and BarnesH. L.: ‘Reaction pathways in Fe-S system below 100 °C’, Chem. Geol.200016725. doi: 10.1016/S0009-2541(99)00198-9
43.
TaylorP.: ‘The stereochemistry of iron sulfides—a structural rationale for the-crystallization of some metastable phases from aqueous solution’, Am. Mineral.1980651026,
44.
Osseo-AsareK. and WeiD.: “Semiconductor electrochemistry of coal pyrite”. Department of Materials Science and Engineering. United States Department of Energy. 1993.
45.
BernerR. A.: ‘Tetragonal iron sulfide’, Science1962137669. doi: 10.1126/science.137.3531.669-a
46.
MuradE.: ‘Magnetic properties of microcrystalline iron(III) oxides and related minerals as reflected in their Mössbauer spectra’, Phys. Chem. Min.199623, 248–262. doi: 10.1007/BF00207766
47.
OloweA. A.PauronB. and GéninJ. M. R.: ‘The influence of temperature on the oxidation of ferrous hydroxide in sulphated aqueous medium: activation energies of formation of the products and hyperfine structure of magnetite’, Corr. Sci.199132, (9), 985–1001. doi: 10.1016/0010-938X(91)90017-J
48.
CookD.: ‘Application of Mössbauer spectroscopy to the study of corrosion’, Hyperfine Interact.200415361–82. doi: 10.1023/B:HYPE.0000024714.84742.fd
49.
GarciaK. E.MoralesA. L.BarreroC. A. and GrenecheJ. M.: ‘New contributions to the understanding of rust layer formation in steels exposed to a total immersion test’, Corros. Sci.2006482813–2830. doi: 10.1016/j.corsci.2005.09.002
