Sulfide Corrosion Research Articles

Preparation and properties study of graphene-enhanced acid-resistant anticorrosion coating for subsea oil and gas

In order to solve the corrosion problem of the existence of acidic material such as H2S, CO2 in the subsea pipelines, this article studied the coating film forming matter, which is combined with phenolic epoxy resin and phenolic aldehyde amine, acid-resistant filler system, etc. With the addition of the graphene dispersion, it significantly improves the abrasive resistance, salt fog resistance, adhesion and chemical character. This article took out the coating with good acid resistance. The results showed that the acid-resistant anticorrosion coating enhanced by graphene has excellent comprehensive physical and chemical properties, such as salt fog resistance, chemical resistance, hydrogen sulfide corrosion resistance, and alkali resistance, which meet the corrosion protection requirements of H2S and CO2 in acidic oil and gas fields subsea pipelines.

Challenge and Review of Hydrogen Sulfide Corrosion Resistance Steels for Oil Country Tubular Goods

Corrosion of oil country tubular goods not only causes huge economic loss, but also brings serious environmental pollution. Stress corrosion cracking of oil country tubular goods in the sulfur-containing environment is the principal corrosion failure form in the exploitation of oil and gas process. Therefore, extensive investigations on hydrogen sulfide corrosion of steels for oil country tubular goods have been carried out. The aim of this work is to review the research progress on the hydrogen sulfide corrosion performance of steels for oil country tubular goods. The influence of alloy elements, defects, environmental factors and mechanical factors on hydrogen sulfide corrosion resistance of steels for oil country tubular goods were discussed. The future work in hydrogen sulfide corrosion performance of oil country tubular good and new sulfur-resistant steels for oil country tubular goods development were prospected.

Perfection of the technology of corrosion-resistant sheet rolled stock production at JSC “Ural Steel”

Manufacturing of field oil pipelines require mainly pipes of 09ГСФ and 13ХФА steels, which correspond to the K52 class of strength. The pipe products and connection details of field oil- and oil products pipelines must meet increased requirements to their resistance against aggressive media, containing water and hydrogen sulfide. At the JSC “Ural Steel”, a unified comprehensive technology of production sheet rolled stock of 09ГСФ and 13ХФА steels in a wide range of assortment. The steels ensure the requirements to hydrogen fracturing as per NACE TM0284 and sulfide corrosion fracturing under stress method A of NACE TM0177 standard. The regimes of controlled sheet rolling with accelerated after-deformation cooling following by a high tempering elaborated. The technology regimes ensure necessary level of mechanical characteristics, corresponding to K52 class of strength. To ensure a satisfactory flatness of sheets, variants of the steels chemical composition depending on finished sheet thickness recommended. The elaborated production regimes ensure metal high resistance at low temperatures and actual value of the impact toughness KCV –40 exceeding considerably the standard requirements. It was shown, that decrease of relation Ca/S in the metal down to ~0,6–1,0 at Sulphur content less than 0.002% does not result in corrosion resistance decreasing and also minimizes the steel liquation inhomogeneity and contamination by non-metallic inclusions. The technology elaborated at JSC “Ural Steel” ensures the possibility of industrial production of corrosion-resistant rolled stock of 09ГСФ and 13ХФА steels in a wide range of assortment.

Investigations of silver sulfide formation on transformer OLTC tap selectors and its influence on oil properties

The on-load tap changer is a vital component of a power transformer. Recently, several utilities have reported the failure of on-load tap changers, suspected to have been caused by silver sulfide corrosion. However, the mechanism of silver sulfide formation has not been well documented in the literature. The silver sulfide influence on transformer oil properties has not been effectively studied either. This paper presents an experimental study on silver sulfide in a transformer, with the view of developing a future test. The reaction between corrosive sulfur in mineral oil, and the silver coating of the tap selector and the resultant silver sulfide film, have been investigated. Silver sulfide is semi-conductive and can reduce the dielectric properties of the oil. Thus, this paper presents breakdown voltage, conduction and permittivity measurements on oil samples with different quantities of silver sulfide. Frequency domain spectroscopy (FDS) technique was used to analyze the transformer oil, in order to determine the influence of silver sulfide on the dielectric losses of oil.

Low-Temperature Pack Aluminization Process on Pipeline Steel To Inhibit Asphaltene Deposition.

Asphaltene deposition in petroleum refineries is known to be problematic as it reduces efficiency and may lead to structural failure or production downtime. Though several successful approaches have been utilized to limit deposition through the addition of dispersants and inhibitors to petroleum, these methods require constant intervention and are often expensive. In this study, we demonstrate an innovative technique to engineer the surface chemistry of pipeline steels to inhibit asphaltene deposition. Pack aluminization, a standard industrial-scale chemical vapor deposition process, is employed at a low temperature of 600 °C to aluminize API 5L X65 high strength pipe steel substrates. The results showed deposit-free steel surfaces after high-pressure and high-temperature fouling experiments. The improvement is attributed to the formation of an aluminide intermetallic phase of Fe2Al5, which changes the native oxide chemistry to favor alumina over hematite. The continuous passivating oxide scale, acting as a protective barrier, mitigates asphaltene deposition and sulfidic corrosion. Because this process is based on alloying the surface of the steel and is not a coating with a weakly adhered interface, it is not prone to delamination, and it can be re-formed when damaged within the aluminized region. The combination of low-cost processing and improved antifouling characteristics makes surface chemistry modification of steel a promising preventative approach against asphaltene deposition.

Microstructure Evolution of the Semi-Macro Segregation Induced Banded Structure in High Strength Oil Tubes During Quenching and Tempering Treatments.

C110 oil well casing tubes should have high strength and corrosion resistance which is commonly used for deep wells operation containing corrosive media. In this paper, the microstructure evolution of a kind of semi-macro segregation originated banded structure in casing tubes is studied under different heat treatments. It is shown that the characteristics of the banded structure will change significantly in subsequent hot working and heat treatment processes. For the hot-rolled ones, the banded structure is composed of pearlite plus bainite. After quenching, it evolves into martensite band with high concentration solute elements. Finally, the banded structure will change into a carbide banding under the following tempering process. The temperature and cooling rate of the tempering practice show an obvious effect on the final band structure. To improve anti-SSC (sulfide stress corrosion cracking) performance, the favorable QT (quenching and tempering) practice for C110 steel should be a higher tempering temperature and a quicker cooling rate, from which the banded structure defects can be decreased together with an obvious improvement of the tube wall hardness uniformity.

Study of the inhibition of hydrogen sulfide corrosion of steel in synthetic stratum water using the complex method

Study of the inhibition of hydrogen sulfide corrosion of steel in synthetic stratum water using the complex method

The Corrosion of Cast Duplex Stainless Steels in Seawater and Sour Brines

Modern duplex stainless steels have been in use since the early 1970s and cast versions of the wrought alloys were soon in demand for pumps and valves. Since that time a range of cast duplex stainless steels have been developed with a wide range of compositions, but all with approximately 50/50 austenite/ferrite phase balance and deliberate additions of nitrogen. This paper presents some comparative corrosion data on a range of cast duplex stainless steels, mainly in seawater. The differences in performance related to composition and microstructure are discussed. Corrosion data in lower chloride brines are also presented to show the limits of use of some lower alloyed duplex materials. In addition to oxidizing chloride solutions, some data are presented on cast duplex stainless steels in reducing brines containing H2S, where the main corrosion problem is sulfide stress corrosion cracking. Finally, the importance of using a suitable technical specification, over and above ASTM, combined with selecting a suitably skilled foundry in order to obtain satisfactory castings is discussed.

Effect of Thiophenes on High-Temperature Corrosion by Sulfidation and Naphthenic Acids

Owing to the depletion of light sweet crude, high-temperature corrosion by sulfidation and naphthenic acids in the oil phase has become one of major challenges for crude oil refineries. The corrosion by model sulfur compounds and naphthenic acids has been extensively studied in laboratories, but the effect of thiophenes, which are widely present in crude oil, is often ignored due to their noncorrosiveness. In the current study, sulfidation and naphthenic acid corrosion are studied in the presence/absence of two model thiophenes, dibenzothiophene and benzothiophene. It is found that thiophenes show an inhibitory effect on naphthenic acid corrosion while not deterring sulfidation significantly. It was proposed that naphthenic acid may corrode the steel, generating iron naphthenates underneath an adsorption layer of thiophenes and producing magnetite.

A Study of the Sulfidation Behavior on Palladium-Coated Copper Wire with a Flash-Gold Layer (PCA) after Wire Bonding

Palladium-coated copper wire with a flash-gold layer (PCA) is an oxidation-resistant fine wire that simultaneously has the properties of palladium-coated copper wire (PCC) and gold-coated copper wire. This research used an extreme sulfidation test to compare corrosion resistance between the PCC and PCA wires. In addition to closely examining the morphology of the wires, the internal matrix after the sulfidation test is also discussed. In doing so, the PCA wire was bonded onto the aluminum pads and the sulfidation test was conducted. Then, we observed its morphology and elemental distribution and found that the flash-gold layer of the PCA wire effectively enhanced resistance to sulfidation corrosion. Because the copper ball had an alloying effect on the ball bonding, it produced different shapes of sulfide after the sulfidation test. The degree of corrosion on the wedge bond was different because of the presence or absence of the coated layer. In contrast, the flash-gold layer of the PCA wire enhanced the bonding force and retained low resistance characteristics after the sulfidation test.

Mechanism analysis of bubbling corrosion caused by boiler flue gas on metal material

Hydrogen bubbling is a typical corrosion morphology caused by hydrogen sulfide corrosion. In order to explore hydrogen sulfide corrosion of iron, the composition of flue gas under actual conditions was simulated in this research. Hydrogen sulfide corrosion in flue gas of four kinds of materials selection of ground process pipeline and underground pipe string was researched experimentally. The pressure and temperature of hydrogen bubbling corrosion morphology under actual flus gas conditions were obtained. The electrochemical corrosion mechanism between iron and hydrogen sulfide was investigated.

Failure analysis of hall-effect sensors in brushless DC starter/generator

Atmospheric corrosion is one of the most common failure phenomena in copper-containing components of areoengine due to corrosive gases and high temperature. This paper described a failure analysis of hall-effect sensors in an areoengine brushless direct-current (BLDC) starter/generator. The failure analysis experiments were performed with electrical performance test, external visual inspection, X-ray inspection, internal visual inspection, scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). Short-current failure was ascertained as failure mode of the hall-effect sensors by electrical performance test. Internal visual inspection, SEM and EDS were conducted to determine the failure mechanism of the samples as copper sulfide (Cu2S) corrosion. Moreover, validation experiments were carried out to confirm the results of failure analysis in which the failure of another sample was stimulated under 120 Centigrade for three hours. Some failure causes of the hall-effect sensors were inferred and some recommendations for the optimum design of hall-effect sensor modules were elaborated.

The Effect of Polydopamine on an Ag-Coated Polypropylene Nonwoven Fabric.

A practical method for preparing multifunctional polypropylene (PP) nonwoven fabrics with excellent stability and durability was explored. First, the PP nonwoven fabric was sputtered by a magnetron sputtering system to form an Ag film on the surface of the fabric. Subsequently, the coated fabric was treated with dopamine. The fabrics were characterized by scanning electron microscopy (SEM), an energy dispersive spectrometer (EDS), electrical conductivity, electromagnetic interference shielding effectiveness (EMI SE), antibacterial activity, stability, and laundering durability. The results of the study revealed that the fabric was coated with Ag, and after the treatment with dopamine, the surfaces of Ag-coated fibers were coated with polydopamine (PDA). The fabrics still had a sheet resistance below ~15 Ω/sq and exhibited excellent EMI SE above ~25 dB, though few differences existed from the single Ag-coated sample. After the treatment with dopamine, the antibacterial activity of the fabric was enhanced. Meanwhile, the treated samples exhibited excellent resistance against sodium sulfide corrosion, which could enhance the stability of the Ag-coated fabric. Moreover, the laundering durability of the treated fabric was improved in the same process, whose lowest sheet resistance was ~18 Ω/sq and the EMI SE was ~8 dB more than single Ag-coated PP nonwoven fabrics. In conclusion, this method was considered to be effective in fabricating multifunctional, stable, and durable fabrics.

Analysis of Effect of Protective Coatings on the Rate of Corrosion in Reinforced Concrete Sewers Microscopic Study

Microbial induced corrosion (MIC) in reinforced concrete (RC) sewers are increasing in occurrence and severity which is leading to significant economic losses. Being able to prevent or significantly reduce the rate of MIC in RC sewers will be of great help in finding a suitable sustainable solution. This study has investigated the effect of MIC; sulphide corrosion, on RC sewers through analytical techniques; scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). The aim was to create a sustainable solution; protective epoxy coating (PEC), that will be capable of preventing or significantly reducing the MIC in RC sewers. The PEC based solution was able to significantly reduce the MIC in RC sewers. Furthermore, the test results also outlined that even in the coated sample, crown corrosion was more as compared to the corrosion of the submerged portion of the sample.

Analysis of Effect of Protective Coatings on the Rate of Corrosion in Reinforced Concrete Sewers Microscopic Study

Microbial induced corrosion (MIC) in reinforced concrete (RC) sewers are increasing in occurrence and severity which is leading to significant economic losses. Being able to prevent or significantly reduce the rate of MIC in RC sewers will be of great help in finding a suitable sustainable solution. This study has investigated the effect of MIC; sulphide corrosion, on RC sewers through analytical techniques; scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). The aim was to create a sustainable solution; protective epoxy coating (PEC), that will be capable of preventing or significantly reducing the MIC in RC sewers. The PEC based solution was able to significantly reduce the MIC in RC sewers. Furthermore, the test results also outlined that even in the coated sample, crown corrosion was more as compared to the corrosion of the submerged portion of the sample.

Development of SiO2/TiO2/Al2O3-based/TiO2 coating for preventing sulfide corrosion in thermal power plant boilers

In thermal power generation equipment, wall thinning on boiler tubes due to sulfide corrosion has been a problem. The methods for resolving or preventing the problem are coating of a nickel-chromium film by plasma spraying, weld cladding, and replacement of water wall tubing. These methods are expensive and time consuming. Therefore, an economical and straightforward coating technique was developed for preventing sulfide corrosion on boiler tubes. The developed coating has a four-layered structure comprising, in order from the boiler tube substrate, thin films of (1) a SiO2 layer, (2) a TiO2 layer, (3) an Al2O3-based layer, and (4) a TiO2 layer. The coating reduced corrosion to 25% or less compared with an uncoated part under a simulated condition (Gas: CO2/H2/N2/CO/H2O = 12%/4%/67%/8%/9% H2S 330 ppm, Temperature: 500 °C). It was found that the coating on boiler tubes is exceptionally durable and continues to be effective for more than 2 years in actual power plants. This coating process can be applied to a large area, and the work period is short. When the coating area is 100 m2, the working time is 3 days and total spraying time is only 7 h.

Pervasively anoxic surface conditions at the onset of the Great Oxidation Event: New multi-proxy constraints from the Cooper Lake paleosol

Oceanic element inventories derived from marine sedimentary rocks place important constraints on oxidative continental weathering in deep time, but there remains a scarcity in complementary observations directly from continental sedimentary reservoirs. This study focuses on better defining continental weathering conditions near the Archean-Proterozoic boundary through the multi-proxy (major and ultra-trace element, Fe and Cr stable isotopes, µ-XRF elemental mapping, and detrital zircon U-Pb geochronology) investigation of the ca. 2.45 billion year old (giga annum, Ga) Cooper Lake paleosol (saprolith) developed on a sediment-hosted mafic dike within the Huronian Supergroup (Ontario, Canada).Throughout the variably altered Cooper Lake saprolith, ratios of immobile elements (Nb, Ta, Zr, Hf, Th, Al, Ti) are constant, indicating a uniform pre-alteration dike composition, lack of extreme pH weathering conditions, and no major influence from ligand-rich fluids during weathering or burial metasomatism/metamorphism. The loss of Mg, Fe, Na, Sr, and Li, a signature of albite and ferromagnesian silicate weathering, increases towards the top of the preserved profile (unconformity) and dike margins. Coupled bulk rock behaviour of Fe-Mg-Mn and co-localization of Fe-Mn in clay minerals (predominantly chlorite) indicates these elements were solubilized primarily in their divalent state without Fe/Mn-oxide formation. A lack of a Ce anomaly and immobility of Mo, V, and Cr further support pervasively anoxic weathering conditions. Subtle U enrichment, if primary, is the only geochemical evidence that could be consistent with oxidative element mobilization. The leaching of ferromagnesian silicates was accompanied by variable mobility and depletion of transition metals with a relative depletion order of Fe ≈ Mg ≈ Zn > Ni > Co > Cu (Cu being significantly influenced by secondary sulfide formation). Mild enrichment of heavy Fe isotopes (δ56/54Fe from 0.169 to 0.492‰) correlating with Fe depletion in the saprolith indicates open-system loss of isotopically light aqueous Fe(II). Minor REE + Y fractionation with increasing alteration intensity, including a decreasing Eu anomaly and Y/Ho ratio, is attributed to albite breakdown and preferential scavenging of HREE > Y by clay minerals, respectively. Younger metasomatism resulted in the addition of several elements (K, Rb, Cs, Be, Tl, Ba, Sn, In, W), partly or wholly obscuring their earlier paleo-weathering trends.The behavior of Cr at Cooper Lake can help test previous hypotheses of an enhanced, low pH-driven continental weathering flux of Cr(III) to marine reservoirs between ca. 2.48–2.32 Ga and the utility of the stable Cr isotope proxy of Mn-oxide induced Cr(III) oxidation. Synchrotron µ-XRF maps and invariant Cr/Nb ratios reveal complete immobility of Cr despite its distribution amongst both clay-rich groundmass and Fe-Ti oxides. Assuming a pH-dependent, continental source of Cr(III) to marine basins, the Cr immobility at Cooper Lake indicates either that signatures of acidic surface waters were localized to uppermost and typically unpreserved regolith horizons or were geographically restricted to acid-generating point sources. However, given detrital pyrite preservation in overlying fluvial sequences, it is probable that the oxidative sulfide corrosion required to drive surface pH < 4 lagged behind in this region relative to other early Proterozoic sequences. The entire saprolith exhibits a consistently light stable Cr isotope composition (δ53/52Cr: −0.321 ± 0.038‰, 2sd, n = 34) that cannot be linked to Cr(III) oxidation and is instead interpreted to have a magmatic origin.The combined paleosol chemical signatures and preservation of detrital pyrite/uraninite indicate low atmospheric O2 during weathering at ca. 2.45 Ga in the rift-related environment of the Lower Huronian. The aqueous flux from the reduced weathering of mafic rocks was presumably characterized by a greater transition metal (Fe, Mn, Zn, Co, Ni) load with isotopically light Fe(II) compared to modern environments, as well as higher Eu/Eu* and Y/Ho than the source rock. In most models of Precambrian ocean element inventories, hydrothermal fluids are viewed as the main supplier of several metals (e.g., Fe, Zn), although the results herein suggest that a riverine metal supply may have been substantial and that using Eu-excess as a strict proxy for hydrothermal flux may be misleading in near-shore marine sedimentary deposits.

НАУЧНЫЕ ОСНОВЫ РАЗРАБОТКИ И МЕТОДОЛОГИЯ СОЗДАНИЯ СТАЛЕЙ ДЛЯ ПРОИЗВОДСТВА НЕФТЕПРОМЫСЛОВЫХ ТРУБ ПОВЫШЕННОЙ ПРОЧНОСТИ И КОРРОЗИОННОЙ СТОЙКОСТИ

The authors carried out the survey of the crashworthiness of the oil-field and transportation equipment and noted the significant (by times, and sometimes dozens of times) exceeding of the allowable reliability index of the pipeline systems according to the values of the specific failure rate (item/km/year). It is shown that the main reason for pipe degradation and fracture is the internal corrosion which, depending on the composition of produced fluids, is manifested by one predominant type or the combination of several types of stress-corrosion fracture: hydrogen cracking, sulfide stress corrosion cracking, carbon dioxide, sulfide, and bacterial corrosion. Based on the generalization and systematization of the results of numerous research and applied works on the development and utilization of new pipe steels with the increased strength and corrosion resistance, the main scientific ideas of the formation of steel corrosion resistance in the highly aggressive oil-field fluids are proposed. The authors developed the methodology and offered the sequence of measures (algorithm) to solve set problems on the development of steels for production of oil pipes with higher mechanical properties and the resistance to stress-corrosion fracture. A list of necessary research, tests, and requirements to the product quality is defined. The authors proved the rationality of used approaches, methods, and decisions on the alloying, microalloying, modifying, and selection of the structural condition of the developed steels and on the technology of pipe production. The paper presents the examples of the development of new steels with the increased strength and corrosion resistance and, consequently, for the efficient solution of issues of the improvement of the performance characteristics of oil-and-gas pipeline and oil-well tubes.

Corrosion resistance of ZrO2 films under different humidity coal gas conditions at high temperature

ZrO2 films were prepared on 304 stainless steel by sol-gel method. The resistance of ZrO2 films to high temperature and high humidity coal gas corrosion was studied. Experiments show that the film on the surface of the sample without vacuum treatment is ZrO2-Cr2O3-Fe2O3 (ZrO2-passivation film) composite film. This film is effective against intergranular corrosion, however, as the corrosion humidity increases, sulfide corrosion occurs on the surface of the coated sample. The XPS test showed no change in the composition of the ZrO2 film before and after etching. The sulfide of the sample is caused by Cr2O3-Fe2O3. The high density ZrO2 film is very resistant to high temperature coal-gas corrosion.

Manufacturing technologies of steel seamless tubes for production of hard-to-recover hydrocarbons

The review contains main directions in the development of modern steelmaking, hot rolling technologies and heat treatment aimed to follow increased requirements to seamless tubes for production of oil and gas under severe conditions. New targets of PJSC “Gazprom” in development of new resources have determined new technical requirements to pipes for low temperature application, resistant to hydrogen sulfide and carbon dioxide corrosion. Basic metal science approaches are given to develop new chemical compositions of high quality steels containing minimum of sulfur, phosphorous and solute gases. Corresponding heat treatment routes are determined for formation of martensitic microstructure in full wall section during quenching with subsequent high tempering for required combination of high strength and ductility. It was shown that optimal combination of high strength and toughness at 60 °C below zero can be achieved by alloying of chromium-molybdenum steel containing about 0.25 wt. % of carbon with strong carbon forming elements such as vanadium and niobium. Sustainability of these steels to stress sulfide cracking was achieved through grain refinement with microalloying by molybdenum in concentrations corresponding to strength grades that gives high hardenability and retards tempering of martensite. New compositions of corrosion resistant martensitic 13 % chromium steel were carried out that was resulted in required resistance to carbon dioxide environments with improved low temperature toughness and high strength. The authors present results of reconstruction of steel making and hot rolling production lines at JSC “Volzhskii Pipe Plant” providing the required quality of new products from continuously cast steel billets to finished tubes.