Bildiri MetinleriKonferanslar, toplantılar, paneller, çalıştaylar vb.https://hdl.handle.net/11630/65282024-03-29T00:32:57Z2024-03-29T00:32:57ZEffect of H2S and CO2 on Cement/Casing alloy interface corrosion integrity for cold climate oil and gas well applicationsFeng, R.Beck, JustinHall, D.M.Büyüksağiş, AyselZiomek-Moroz, M.Lvov, S.N.https://hdl.handle.net/11630/75942021-05-14T12:56:40Z2016-01-01T00:00:00ZEffect of H2S and CO2 on Cement/Casing alloy interface corrosion integrity for cold climate oil and gas well applications
Feng, R.; Beck, Justin; Hall, D.M.; Büyüksağiş, Aysel; Ziomek-Moroz, M.; Lvov, S.N.
A study has been carried out to investigate sweet and sour corrosion at the cement-casing interface for offshore oil and gaswells in cold climate. The test solution chemistry was determined by sampling pore water from cement exposed in an autoclavesystem to brine and CO2 at 100 °C and 10 MPa. The extracted pore water was used to define the composition of a cement simulated pore solution (CSPS),which was then used for the ensuing corrosion tests. Samples made of high strength casing steel, grade Q125, were exposedto the CSPS at 4 °C and 10 MPa in CO2-only and two mixed CO2-H2S environments. The corrosion rate measured in-situ with linear polarization resistance and electrochemical impedance spectroscopywas generally found to range between 10 and 20 μm y-1 after 60 hours of exposure, with the average corrosion rate decreasing slightly with increasing H2S content. The corrosion potential, measured versus a custom high pressure Ag/AgCl electrode, was also found to shift slightlyin the negative direction as the H2S content increased. The corrosion products were determined using scanning electron microscopy (SEM) and energy-dispersiveX-ray spectroscopy (EDS). The corrosion products had the chemical compositions close to iron carbonate and iron oxide. Sulfurwas detected in the inner film region when H2S was present. These results were compared to the corrosion rates and Pourbaix diagrams modeled using commercial software.The reaction mechanisms are discussed in the paper based on the potentiodynamic polarization measurements and electrochemicalimpedance spectroscopy taking into account the modeled solution speciation of the CSPS and corrosion product film.
2016-01-01T00:00:00ZCorrosion of 13Cr steel at the Cement/Casing interface in CO2/H2S environments at 4, 85 and 200 °CBeck, JustinFeng, R.Hall, D.M.Büyüksağiş, AyselLvov, S.N.Ziomek-Moroz, M.https://hdl.handle.net/11630/75922020-04-01T07:57:02Z2018-01-01T00:00:00ZCorrosion of 13Cr steel at the Cement/Casing interface in CO2/H2S environments at 4, 85 and 200 °C
Beck, Justin; Feng, R.; Hall, D.M.; Büyüksağiş, Aysel; Lvov, S.N.; Ziomek-Moroz, M.
A study was carried out to investigate corrosion at the cement/casing interface for 13Cr casing steel. Cement simulated pore solution (CSPS) was developed by exposing cement pieces to 5% NaCl at 100 °C and 10 MPa in equilibrium with CO2. Pore solution was extracted from the cement pieces using a die press. Chemical analysis of the pore solution extract was performed and used for preparing CSPS for 13Cr corrosion testing. Corrosion tests were performed in CSPS at equilibrium with CO2 or CO2+H2S at 10 MPa at 4, 85, and 200 °C. Corrosion rates were determined using linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), and mass loss coupons. Addition of H2S at 4 °C increased the corrosion rate, while at 85 °C it slightly decreased the corrosion rate. Only a small effect from H2S addition was observed at 200 °C. Cyclic voltammetry (CV) results showed passivation/depassivation of 13Cr in CSPS at 4 and 85 °C, while a transition to active corrosion was observed at 200 °C. Surface analysis using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) found that both the coverage and complexity of the corrosion products formed increased dramatically with increasing temperature.
2018-01-01T00:00:00ZEffects of CO2 and H2S on corrosion of martensitic steels in NaCl(aq) at low temperatureFeng, R.Beck, JustinHall, D.M.Büyüksağiş, AyselZiomek-Moroz, M.Lvov, S.N.https://hdl.handle.net/11630/75912020-04-01T07:43:51Z2016-01-01T00:00:00ZEffects of CO2 and H2S on corrosion of martensitic steels in NaCl(aq) at low temperature
Feng, R.; Beck, Justin; Hall, D.M.; Büyüksağiş, Aysel; Ziomek-Moroz, M.; Lvov, S.N.
Corrosion studies were conducted for martensitic carbon steels in brine solutions at 4 °C and 10 MPa (1450 psi), which simulated the subsurface environments encountered in Arctic drilling. Three environments with a 5 % wt. NaCl brine were used: (1) 0.312 mole of CO2 per mole of H2O in brine, (2) 3.12 x 10-4 mole of H2S per mole of H2O in brine, and (3) a mixture of 3.12 x 10-4 mole H2S and 0.312 mole CO2 per mole of H2O in brine. Two martensitic carbon steels were selected for the investigations: a high strength low alloy (HSLA) carbon steel commonly used for drill pipe (G41000) and a newly designed ultra-high strength low alloy (UHSLA) steel (G41300). Electrochemical and mass loss measurements found corrosion rates on the order of 0.05 mm y-1 in the systems containing H2S and CO2+H2S, while the CO2 systems saw corrosion rates between 0.5 and 2 mm y-1. Surface analyses of the tested samples were performed using scanning electron microscopy and energy dispersive X-ray spectroscopy to identify corrosion products. The corrosion products were unstable and oxidized quickly after taking out of the system. All samples had a high oxygen content across the surface, though the samples exposed to H2S and CO2+H2S had relatively higher levels of sulfur present in an inner region of the film. Experimental corrosion rates were compared to model predictions, and a good agreement was found for the CO2 and H2S cases. However, the model predicted that corrosion rates in the mixed case would match those of the CO2-only system. The experimental results showed that CO2:H2S ratios as high as 1000 can result in predominantly sour corrosion at the low temperature, high pressure conditions tested.
2016-01-01T00:00:00ZCorrosion behavior of ultra-high strength drilling steel in alkaline brines containing hydrogen sulfide at high temperatureFeng, R.Beck, JustinHall, D.M.Büyüksağiş, AyselZiomek-Moroz, M.Lvov, S.N.Wolfe,I.https://hdl.handle.net/11630/75902020-04-01T08:02:01Z2016-01-01T00:00:00ZCorrosion behavior of ultra-high strength drilling steel in alkaline brines containing hydrogen sulfide at high temperature
Feng, R.; Beck, Justin; Hall, D.M.; Büyüksağiş, Aysel; Ziomek-Moroz, M.; Lvov, S.N.; Wolfe,I.
In-situ electrochemical measurements were used to study the sour corrosion of ultra-high strength low alloy carbon steel (UHSLA) in alkaline brines at 200 °C. The solutions were buffered with NaHCO3 / Na2CO3 / NaOH to pH values calculated to be 8.1, 9.8, and 10.8 with the presence of H2S gas at 200 °C. The partial pressure of H2S was equivalent to 10 psi (69 kPa) at 85 °C. According to thermodynamic calculations, the dominant reactive ion changed from HCO3-(aq) to OH-(aq) with a comparable concentration of HS-(aq) as pH increased. Measured polarization resistance values at 200 °C were one to two orders of magnitude lower than those at 85 °C, which corresponded to a drastic increase in corrosion rate. After 60 hours, the corrosion rates (CR) were 0.84 mm y-1, 2.88 mm y-1, and 1.83 mm y-1 from pH 8.1 to 10.8. The CR calculated with commercial software was in reasonable agreement with the experimental CR. Limiting current was observed in the anodic region using linear sweep voltammetry (LSV) but not in the cathodic region. Even with the effect of limiting current, anodic Tafel slopes, ba, were able to be gathered from LSV using a new method derived from the generalized Butler-Volmer equation. The ba values indicated that the anodic reactions followed the Bockris mechanism at pH 8.1 and a two-electron mechanism at pH 9.8 and 10.8. Cathodic Tafel slopes corresponded to a two-electron mechanism in the three conditions. Two layers were observed on the surface at pH 8.1 and 9.8, and the outer layer spalled off in some regions. As the pH increased, the major corrosion products transitioned from pyrrhotite/siderite to magnetite, and the S distribution moved outward from the inner layer.
2016-01-01T00:00:00Z