TY - THES

T1 - Hydrogen uptake and permeation in steels for oil and gas production and comparison with ARMCOTM-Fe

AU - Raab, Sabrina

N1 - no embargo

PY - 2022

Y1 - 2022

N2 - The demand for renewable energy sources like hydrogen is rising and gaining importance as the global energy market is currently facing a period of transition to combat ongoing global warming. However, even the most optimistic energy mix includes oil and gas as a key energy carrier towards the end of the century. Hydrogen is a possible future energy carrier but can be a harmful element for metals and their alloys due to its small size and the related potential to propagate within the material. To ensure the safe and smooth transport and storage of hydrogen, it is crucial to avoid hydrogen damage. Therefore, it is of utmost importance to comprehend how much hydrogen can be absorbed by the material under operating conditions and how absorbed hydrogen affects the properties of the materials used. The aim of this thesis is to study the question of how much hydrogen can be absorbed by certain steel grades used in the oil and gas industry under different conditions, which mechanisms are responsible for this, and whether the diffusion coefficient of hydrogen varies depending on the type of charging. The hydrogen uptake and permeation of three different types of carbon steels (J55, L80, P110) and ARMCO-Fe were investigated to evaluate the diffusion coefficient. The techniques used for the permeation measurements include pressure permeation with gaseous hydrogen at 100 bar, permeation at open circuit potential (OCP), and electrochemical hydrogen permeation at a current density of 1 mA/cm^2. For the analysis of hydrogen uptake, cathodic charging and immersion tests were carried out, both at ambient temperature in NaCl solution with thiourea added. The loading time for both methods was between 1 hour and 72 hours. In addition, the hydrogen uptake was also investigated utilizing autoclave tests with gaseous hydrogen at elevated pressure for a test duration between 1 and 168 hours. Following that, the absorbed hydrogen content was analyzed, and diffusion curves were fitted for the evaluation process. To assess the hydrogen diffusivity, the diffusion coefficients of all applied techniques were calculated, and the results of J55, L80, and P110 were compared to those of ARMCO iron. The results indicate an increased hydrogen uptake for the steel grades used in the oil and gas industry compared to ARMCO iron. Moreover, the effective diffusion coefficient of hydrogen for oilfield steel grades is between one or two orders of magnitude lower than that of ARMCO iron.

AB - The demand for renewable energy sources like hydrogen is rising and gaining importance as the global energy market is currently facing a period of transition to combat ongoing global warming. However, even the most optimistic energy mix includes oil and gas as a key energy carrier towards the end of the century. Hydrogen is a possible future energy carrier but can be a harmful element for metals and their alloys due to its small size and the related potential to propagate within the material. To ensure the safe and smooth transport and storage of hydrogen, it is crucial to avoid hydrogen damage. Therefore, it is of utmost importance to comprehend how much hydrogen can be absorbed by the material under operating conditions and how absorbed hydrogen affects the properties of the materials used. The aim of this thesis is to study the question of how much hydrogen can be absorbed by certain steel grades used in the oil and gas industry under different conditions, which mechanisms are responsible for this, and whether the diffusion coefficient of hydrogen varies depending on the type of charging. The hydrogen uptake and permeation of three different types of carbon steels (J55, L80, P110) and ARMCO-Fe were investigated to evaluate the diffusion coefficient. The techniques used for the permeation measurements include pressure permeation with gaseous hydrogen at 100 bar, permeation at open circuit potential (OCP), and electrochemical hydrogen permeation at a current density of 1 mA/cm^2. For the analysis of hydrogen uptake, cathodic charging and immersion tests were carried out, both at ambient temperature in NaCl solution with thiourea added. The loading time for both methods was between 1 hour and 72 hours. In addition, the hydrogen uptake was also investigated utilizing autoclave tests with gaseous hydrogen at elevated pressure for a test duration between 1 and 168 hours. Following that, the absorbed hydrogen content was analyzed, and diffusion curves were fitted for the evaluation process. To assess the hydrogen diffusivity, the diffusion coefficients of all applied techniques were calculated, and the results of J55, L80, and P110 were compared to those of ARMCO iron. The results indicate an increased hydrogen uptake for the steel grades used in the oil and gas industry compared to ARMCO iron. Moreover, the effective diffusion coefficient of hydrogen for oilfield steel grades is between one or two orders of magnitude lower than that of ARMCO iron.

KW - Hydrogen permeation

KW - Hydrogen uptake

KW - Carbon steel

KW - Hydrogen diffusion

KW - Oil and gas production

KW - Corrosion

KW - ARMCO iron

KW - Wasserstoff Permeation

KW - Wasserstoffaufnahme

KW - Kohlenstoffstahl

KW - Wasserstoff Diffusion

KW - Korrosion

KW - Öl und Gas Produktion

KW - ARMCO-Eisen

M3 - Master's Thesis

ER -