P110 Steel Research Articles

Major corrosion influence factors analysis in the production well of CO2 flooding and the optimization of relative anti-corrosion measures

Major corrosion influence factors in the production well of CO2 flooding in Xinjiang oilfield were investigated, and corresponding anticorrosion measures (relating to corrosion inhibitors and corrosion-resistant alloys) had been contrasted in order to select a most suitable scheme to solve the tubing corrosion issue. The results showed that the corrosion of N80 steel in liquid phase was mainly affected by temperature, while in gas phase by temperature and CO2 partial pressure. As to the corrosion of 3Cr steel, in liquid phase, the influencing factors were temperature and chloride concentration, and in gas phase, it was mainly affected by temperature. The safe service life of N80 and P110 steel in liquid phase were less than 8 years, whereas that of 9Cr and 13Cr steel both exceeded 30 years. In gas phase, the safe service life of N80 and P110 steel were 11.65 years and 16.55 years respectively, while that of 3Cr, 9Cr and 13Cr steel were more than 30 years. Suitable for production well in CO2 flooding, No.6 corrosion inhibitor was selected. The corrosion rate of tubing could be controlled within 0.076 mm/y by adding 1000 ppm corrosion inhibitor. 9Cr steel was recommended to be used as the tubing of new production wells for CO2 flooding, and, for old wells, the method of continuous filling corrosion inhibitor was recommended to resist corrosion.

Chemically modified guar gum and ethyl acrylate composite as a new corrosion inhibitor for reduction in hydrogen evolution and tubular steel corrosion protection in acidic environment

The paper deals with the synthesis of Guar gum and ethyl acrylate (GG-EEA) composite. The synthesized natural polysaccharide composite was used as a corrosion inhibitor to reduce hydrogen evolution and P110 steel corrosion protection in 15% HCl (Hydrochloric acid). The primary corrosion techniques like weight loss, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) was used to analyze the corrosion inhibition process. The PDP proposed that GG-EEA composite is a mixed-type corrosion inhibitor and inhibits corrosion by blocking the active sites presenting over the metal surface. The corrosion inhibition performance of GG alone is 77.5%, and that of GG-EEA is 92.3% at 500 mg/L. The adsorption of GG-EEA onto P110 steel is spontaneous and mixed type, i.e., both physical and chemical. The conformation of GG-EEA molecule adsorption was done using a scanning electron microscope (SEM), Energy dispersive x-ray spectroscopy (EDX), Atomic force microscopy (AFM), and X-ray photoelectron spectroscopy studies. Density functional theory (DFT) analysis was done to explore the active sites over the inhibitor in metal-inhibitor interaction. Molecular dynamic simulation (MD) simulations study reveals that GG-EEA has more adsorption capacity than GG alone.

The localized corrosion of mild steel in carbonated cement pore solution under supercritical carbon-dioxide in a simulated geothermal environment

Cement carbonation, one of the main causes of the reinforced concrete corrosion, is also inevitable in the geological environment of carbon sequestration, possibly destroying the integrity of well/cement system. To evaluate the corrosion risk of casing pipe in a geothermal well environment, the corrosion behavior of P110 steel was investigated in carbonated cement pore solutions under carbon dioxide supercritical conditions. It was found that a dense FeCO3 layer was generally formed and it could effectively prevent the steel from corrosion. However, above the threshold concentrations of chloride ion and dissolved oxygen, localized corrosion protrusions could be observed, which might continuously grow larger and higher until its outer shell ruptured during the exposure of the steel substrate in the simulated environment. The expansive growth of the protrusion could be attributed to the active dissolution accelerated by chloride ion at the bottom and the cooperative formation of iron oxide and carbonate in the core region. Such a localized corrosion damage could occur at the casing/cement interface in practice and may become a fatal threat to casing pipes for carbon sequestration in the oil/gas industry.

Effect of stress on the crevice corrosion of P110 steel in the CO2-saturated NaCl solution containing thiosulphate/H2S

ABSTRACT The effect of stress on the crevice corrosion of P110 carbon steel in the CO2-saturated 3.5 wt-% NaCl solution with a small amount of thiosulphate/H2S was investigated. The results showed that the composition of corrosion products on the steel surface did not change with elastic stress while the mackinawite film formed at the crevice mouth was more easily spalled off under higher stresses. Further, the elastic stress likely promoted localised corrosion but inhibited uniform corrosion both inside and outside crevice. Increasing the applied stress led to a deeper and sharper corrosion groove covering with corrosion products at the crevice mouth, suggesting the crevice corrosion was promoted by the applied stress. This is likely due to the peeling of mackinawite film and stress concentration at the crevice mouth.

Early identification of stress corrosion cracking of P110 low alloy steel in downhole fluid by electrochemical noise measurement

ABSTRACT Electrochemical noise (EN) measurements were applied to detect the stress corrosion cracking (SCC) of API P110 low alloy steel in simulating CO2-containing downhole fluid during the slow strain rate test (SSRT). Several statistical parameters of potential and current transients were defined, and they were proven to be indicative of the metastable and stable pitting, as well as the initiation and propagation processes of microcracks. The EN results showed that the amplitude and lifespan of current transients increase with the CO2 concentration. The increasing SCC susceptibility of P110 steel is mainly attributed to the decreasing pH at the crack tip, which not only accelerated the rupture of passive film on crack walls but also prolonged the lifespan of cracks advance. EN measurement may be a promising technique for the early diagnosis of SCC.

Corrosion inhibition and adsorption of imidazolium based ionic liquid over P110 steel surface in 15% HCl under static and dynamic conditions: Experimental, surface and theoretical analysis

The present paper deals with the corrosion inhibition evaluation of imidazoline based ionic liquid, namely 1-Decyl-3-methylimidazolium chloride (DMIC) on P110 steel in 15% HCl under static and dynamic conditions. The influence of KI addition was also examined over the inhibition performance (ɳ%). EIS results reveal that Rct increase with increases in DMIC concentration. PDP suggests that the inhibition action of DMIC is a mixed type inhibitor. The inhibitive performance of DMIC is less, and its maximum inhibition efficiency is 68.61% at 400 mg/L. Addition of KI (0.5 mM) + DMIC (400 mg/L) enhanced the corrosion inhibition efficiency to 90.15%. The performance of DMIC and DMIC+KI decreases with an increase in temperature. The adsorption of DMIC obeys the El-Awady isotherm. The performance of DMIC is better under hydrodynamic conditions as compared to static conditions. The performance of DMIC decreases when the rotation speed is higher than 1500 rpm. Density functional theory (DFT) suggests that both anionic/cationic parts help in the DMIC adsorption. Molecular dynamic simulation (MD) reveals that neutral DMIC adsorbed flatly over P110 steel while protonated adsorbed in a twisted manner.

Structural integrity assessment of a 5CT P110 steel riser pipe according to BS 7910:2013 standard

In this work we performed a structural integrity assessment of a riser pipe made of a material with a novel application, the API 5CT P110 steel, with superficial semi-elliptical cracks in the longitudinal position. The behavior of different crack size on a pipe under specific boundary conditions and pressure loads was studied. With the Finite Element Method, the Stress Intensity Factors along the crack front were obtained and compared with the Stress Intensity Factors calculate by the analytical approach of BS 7910:2013 standard. Afterwards, the fracture toughness of API 5CT P110 steel was obtained through CTOD tests to plot a specific Failure Assessment Diagram according the Option 1 of BS 7910:2013, in order to determine the acceptability of the cracks. The critical crack depths in the studied conditions were 14.2 mm according to the analytical approach of BS 7910:2013 standard and 15.5 mm according to FEM analysis.

Investigations of Mechanical Properties of API P110 Steel Casing Tubes Operated in Deep-Sea Sour Condensate Well Conditions

Abstract Due to the complexity of the marine environment, in deep-sea drilling, all kinds of strings are corroded by different deep-sea conditions for a long time, accompanied by high temperature and high pressure, which lead to the continuous change of mechanical properties of materials. In order to solve the problem that the material mechanical parameters cannot be accurately described in the performance analysis of the casing, deep-sea simulated corrosion and material damage experiments of P110 material were carried out in this paper. Mass loss and tensile experiments on corrosion-damaged test pieces were conducted under different corrosion experimental periods. The changes in mechanical properties of the material were analyzed. Equations of the variation of the equivalent yield strength and the equivalent tensile strength were obtained. The results show that the equivalent yield strength and the equivalent tensile strength decrease with the increase of the weight loss rate. Based on the experimental results and finite element analysis, a method for establishing the material corrosion model was proposed in this paper. The deep-sea drilling corrosion performance model of P110 material was established, which greatly reduced the error caused by the material uniformity assumption in finite element analysis. This paper provides a theoretical basis for the analysis of reliability and life of P110 materials in wells.

Aminoantipyrine derivatives as a novel eco-friendly corrosion inhibitors for P110 steel in simulating acidizing environment: Experimental and computational studies

The present paper deals with the synthesis and corrosion inhibition evaluation of aminoantipyrine (AAPs) derivatives on P110 steel in 15% hydrochloric acid solution using standard techniques such as weight loss, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). The predicted toxicity (LD50) values are 1482 mg/kg (AAP-1) and 1380 mg/kg (AAP-2). AAPs are effective corrosion inhibitors giving inhibition efficiency of 95% (AAP-1) at only 400 mg/L concentration. Adsorption of AAPs on the P110 steel surface involves both physical and chemical interactions. The EIS results suggest an increased value of charge transfer resistance with increasing AAPs concentration. PDP result reveals that AAP's are mixed type inhibitors with anodic predominance. SEM, AFM, contact angle and XPS spectra, confirmed the presence of adsorbed inhibitor film. DFT study confirms the participation of both neutral and protonated forms in the corrosion inhibition process. The interaction of AAPs with P110 steel was analyzed by MD simulation that includes the calculation of adsorption energy, RDF, diffusion coefficients, and fractional free volume.

Storage time evaluation of a residue from wine industry as a microencapsulated corrosion inhibitor for 1 M HCl

The effect of a residue from wine industry was investigated as a corrosion inhibitor for API P110 steel in hydrochloric acid. The extract was characterized using Fourier-transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance (1H NMR) and chromatography. The influence of temperature (303–333 K) and grape peel extract concentration were studied using gravimetric and electrochemical experiments. The coupon surfaces were evaluated using microscopy techniques, FTIR-ATR and the contact angle. The by-product exhibited high weight loss efficiencies at 303 K with 4.0 g/L of the extract (83.81%) even after storage. The inhibition increased with the addition of an inorganic enhancer, indicating a synergistic effect between the active compounds and maximum efficiency of 94.48%. Polarization tests indicated that the inhibitor adsorbs on anodic and cathodic regions. The surface characterization techniques confirmed the formation of an organic film and a less attacked surface was observed for the inhibited system.

Inhibition effect of natural polysaccharide composite on hydrogen evolution and P110 steel corrosion in 3.5 wt% NaCl solution saturated with CO2: Combination of experimental and surface analysis

For the analysis of corrosion and hydrogen production inhibition, we have synthesized Guar gum and methylmethacrylate (GG-MMA) composite. The synthesized composite was used as an eco-friendly corrosion inhibitor for P110 steel in 3.5% NaCl solution saturated with carbon dioxide at 50 °C. The primary corrosion techniques like weight loss, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) was used to analyze the corrosion inhibition process. EIS study reveals the kinetically controlled corrosion inhibition process. The results of PDP proposed that GG-MMA composite is the cathodic type of inhibitor. The corrosion inhibition performance of GG-MMA alone is 90% at 400 mg/L, and that of formulation with KI (5 mM) + GG-MMA (300 mg/L) is 96.8%. The adsorption of GG-MMA over P110 steel is spontaneous and mixed type i.e., both physical and chemical. The conformation of GG-MMA molecule adsorption was done using a scanning electron microscope (SEM), Contact angle measurement, Atomic force microscopy (AFM), Scanning Electrochemical Microscopy (SECM) and X-ray photoelectron spectroscopy studies.

A failure case of P110 steel tubing in CO2 flooding well

Purpose This paper aims to analyze a failure case of a P110 tube in a CO2 flooding well. Design/methodology/approach The chemical composition, microstructure and mechanical properties of the failed P110 tubing steel were tested, and met the API Spec 5CT standard. The fractures were investigated by scanning electron microscopy and energy dispersive spectroscopy. Findings Fracture was induced by stress corrosion cracking (SCC) and that the stress concentration caused by the mechanical damage played an important role in the failure. The failure case is a SCC failure affected by mechanical damage and galvanic corrosion. Originality/value The effect of the infiltration of groundwater was studied in the failure case. The stress concentration caused by the mechanical damage played an important role in the failure.

Chitosan derivatives as green corrosion inhibitors for P110 steel in a carbon dioxide environment

Two chitosan derivatives were synthesized for the first time as green corrosion inhibitors for the carbon dioxide corrosion of P110 steel. The structures of the synthesized products were characterized by infrared spectroscopy. Electrochemical and weight-loss experiments were used to test the effect of corrosion inhibitors, while SEM-EDS, AFM and other analysis methods were used to study the protection mechanism of corrosion inhibitors. The experimental results show that synthetic corrosion inhibitors CHC and CAHC are all good corrosion inhibitors for carbon dioxide corrosion inhibition. Both chitosan derivatives can form hydrophobic protective films on the metal surface. For inhibition performance, CAHC is better than CHC, which is the same conclusion drawn from practical experiments and quantum chemical calculations. Investigation into chitosan inhibitors has opened up a new area of research of environmentally friendly corrosion inhibitors, which is of great significance for metal protection without toxicity and side effects.

A novel approach for investigating the effect of flowing fluid on the susceptibility of alloys to environmental stress cracking

The aim of the research is examining the influence of flowing fluid on the susceptibility of materials to environmental stress cracking such as stress corrosion cracking (SCC) and sulfide stress cracking (SSC) using the fracture mechanics circumferential notched tensile (CNT) specimen. A novel SCC/SSC testing flow loop was invented for performing the experimental work. The testing flow loop has been registered as a patent in recognition of its novelty and practical applications in several industries. The experimental conditions were testing the susceptibility of heat treated P110 steel to SSC in deoxygenated stagnant and flowing liquid consisting of 0.01 M Na2S2O3 (as a supplier for H2S) and 3.5 w% NaCl at room temperature. The results indicate that the heat treated P110 steel was susceptible to SSC in stagnant solution, while it was not susceptible in flowing fluid.

Effect of thiosulphate/H2S on crevice corrosion behaviour of P110 carbon steel in CO2-saturated solution

ABSTRACTThe effect of thiosulphate/H2S on crevice corrosion behaviour of P110 carbon steel in the CO2-saturated 3.5 wt% NaCl solution was investigated. The results showed that crevice corrosion of P110 steel could not occur in the CO2-saturated solution, likely due to the inhibition of both anodic and cathodic reactions inside crevice. Further, the structure of corrosion product film along the crevice wall is influenced by the concentration of thiosulphate. Increasing the concentration of thiosulphate to 10−2 mol L−1 promotes the formation of fine flake-like mackinawite outside crevice. In addition, crevice corrosion of P110 steel in the CO2-saturated solution is promoted by increasing the concentration of thiosulphate. This is because the dense and fine mackinawite film on the steel surface has a better protectiveness and could enhance cathodic reaction rate outside crevice.

Investigating the influence of flowing fluid on the resistance of materials to sulfide stress cracking

The study aims to investigate the effect of flowing fluid on the susceptibility of metals and alloys to sulfide stress cracking (SSC) using the fracture mechanics circumferential notched tensile (CNT) specimen. The CNT specimen has never been used in the presence of flowing fluid. A novel testing flow loop was invented for performing the experimental work. The new testing rig can be used for determining the stress intensity factor (KI), threshold stress intensity factor (KIssc), and crack growth rate in flowing fluid for different materials in different corrosive environments at different temperatures. The testing flow loop has been registered as a patent in recognition of its novelty and practical applications in several industries. The experimental conditions were testing the resistance of heat treated P110 steel to SSC in deaerated stagnant and flowing solution containing 0.01 M Na2S2O3 (as a source for H2S) and 3.5 w% NaCl at room temperature. The experimental results show the heat treated P110 steel was susceptible to SSC in stagnant solution, while it was not susceptible in flowing fluid.

Investigations on the oxygen corrosion behaviors of P110 steel in a dynamic experiment simulating nitrogen injection

AbstractNitrogen injection is widely applied to enhance oil recovery, but the corrosion failure risk of tubing and casing is increased by residual oxygen in nitrogen. In this study, the corrosion behaviors of P110 steel under dynamic conditions with different oxygen partial pressures (2.5–0.003 MPa) simulating high‐pressure (30 MPa) nitrogen injection were studied. The morphology and composition of corrosion products were characterized by scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and energy‐dispersive X‐ray analysis methods; furthermore, the localized corrosion rate and three‐dimensional surface morphologies were analyzed. The results show that the general corrosion rate decreased significantly with decreasing O2 partial pressure, especially when O2 partial pressure was below 0.5 MPa, and there is a corrosion morphology change from general corrosion to localized corrosion (pitting). Besides, the localized corrosion rates are about 20 times the general corrosion rates. The corrosion products are mainly FeOOH and Fe3O4. In addition, the scales in the intact area are relatively flat and dense, whereas the damaged scales are porous and brittle. Fluid flows not only changed the morphologies and microstructures, resulting in a more protective product layer but also promoted the transfer of the corrosive mediators and affected the development of localized corrosion.

Downhole O2 corrosion during air-assisted steam injection for secondary or tertiary oil recovery

ABSTRACTAir-assisted steam injection is used as a secondary or tertiary oil recovery technology. During closing, downhole tubular goods are subject to corrosion in a mixed oxygen–steam–hot solution environment. This study investigates the influence of air injection pressure, temperature and Cl− ion concentration in the injection water on the corrosion of P110 steel. Results show that high air injection pressure for increasing oil recovery ratio leads to the highly aggressive corrosion. The trend of corrosion rate and temperature in air-saturated injection water is a reversed ‘V’ curve. However, the high Cl− concentration, which promotes the formation of large holes in the magnetite scale, greatly reduces corrosion. A suitable injection press that balances the oil recovery ratio and corrosion rate of oil tube, avoiding 170°C suitable for the highest corrosion rate, and periodic removing corrosion scales are necessary to inhibit further deterioration of downhole tubular goods.

Co-modification of polydopamine and KH560 on g-C3N4 nanosheets for enhancing the corrosion protection property of waterborne epoxy coating

In this work, the hydrophilic organic films were successfully coated on g-C3N4 nanosheets through facile co-modification of dopamine (DA) and silane coupling agent (KH560). The co-modification of polydopamine (PDA) and KH560 on lamellar g-C3N4 greatly enhanced dispersion of g-C3N4 in aqueous solution and dramatically improved the compatibility and interfacial interaction with waterborne epoxy. The effect of incorporating modified g-C3N4 nanosheets into waterborne epoxy on anticorrosion performance for P110 steel substrates were demonstrated through electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and salt spray test. The results revealed that the |Z|0.01Hz value and percentage coating resistance (Rc) gain (ηc%) of nanocomposite coating increased by 977% and 90.72% with the addition of modified g-C3N4 nanosheets in comparison with pure waterborne epoxy coating, exhibiting outstanding anticorrosion abilities. The reinforced anticorrosion performances of nanocomposite coating could be attributed to the notable shielding effect and well dispersibility of modified g-C3N4 nanosheets.

Inhibition performance of a multi-sites adsorption type corrosion inhibitor on P110 steel in acidic medium

In this work, a multi-site adsorption inhibitor (DBI) was synthesized and characterized. The corrosion inhibition performance of symmetric benzyl lauric acid imidazoline quaternary ammonium salt under 1 M hydrochloric acid (HCl) condition was studied by weight loss test, potentiodynamic polarization curve and electrochemical impedance spectroscopy (EIS), SEM and XRD techniques. The experiment results have shown that the inhibition efficiency increases with an increase in an inhibitor concentration. Potentiodynamic polarization showed that this inhibitor is an anodic-type inhibitor. It is proved that the corrosion inhibitor has high surface properties and good adsorption performance on the surface of P110 steel through the contact angle and surface tension test. Furthermore, the adsorption of the corrosion inhibitor conforms to the Langmuir's adsorption isotherm on the surface of P110 steel.