Development of an electrochemically integrated SR-GIXRD flow cell to study FeCO3formation kinetics.
An electrochemically integrated Synchrotron Radiation-Grazing Incidence X-Ray Diffraction (SR-GIXRD) flow cell for studying corrosion product formation on carbon steel in carbon dioxide (CO2)-containing brines typical of oil and gas production has been developed. The system is capable of generating flow velocities of up to 2 m/s at temperatures in excess of 80 °C during SR-GIXRD measurements of the steel surface, enabling flow to be maintained over the course of the experiment while diffraction patterns are being collected. The design of the flow cell is presented, along with electrochemical and diffraction pattern transients collected from an initial experiment which examined the precipitation of FeCO3onto X65 carbon steel in a CO2-saturated 3.5 wt. % NaCl brine at 80 °C and 0.1 m/s. The flow cell is used to follow the nucleation and growth kinetics of FeCO3using SR-GIXRD linked to the simultaneous electrochemical response of the steel surface which were collected in the form of linear polarisation resistance measurements to decipher in situ corrosion rates. The results show that FeCO3nucleation could be detected consistently and well before its inhibitive effect on the general corrosion rate of the system. In situ measurements are compared with ex situ scanning electron microscopy (SEM) observations showing the development of an FeCO3layer on the corroding steel surface over time confirming the in situ interpretations. The results presented demonstrate that under the specific conditions evaluated, FeCO3was the only crystalline phase to form in the system, with no crystalline precursors being apparent. The numerous capabilities of the flow cell are highlighted and presented in this paper.
Institue of Functional Surfaces, University of Leeds, Leeds LS2 9JT, United Kingdom.
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Burkle
Institue of Functional Surfaces, University of Leeds, Leeds LS2 9JT, United Kingdom.
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De Motte
Institue of Functional Surfaces, University of Leeds, Leeds LS2 9JT, United Kingdom.
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Taleb
Diamond Light Source Ltd., Diamond House, Didcot, Oxfordshire OX11 ODE, United Kingdom.
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Kleppe
Ionix Advanced Technologies, 3M Buckley Innovation Centre, Firth Street, Huddersfield HD1 3BD, United Kingdom.
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Comyn
BP America, Inc., Houston, Texas 77079, USA.
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Vargas
Institue of Functional Surfaces, University of Leeds, Leeds LS2 9JT, United Kingdom.
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Neville
Institue of Functional Surfaces, University of Leeds, Leeds LS2 9JT, United Kingdom.
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Barker