Nucleation of Sweet and Sour Oilfield Corrosion Scales (sponsor: BP; fully funded)
This PhD is part of the EPSRC Centre for Doctoral Training in "Materials for Demanding Environments" [CDT in M4DE], is sponsored by BP and will commence October 2017
SEM image of protective corrosion scale formed on iron in a sweet environment (T = 80°C, pH = 6.8).
Corrosion is an omnipresent concern in oil and gas production. Effective control is essential for maintaining equipment performance and avoiding disasters. This project targets understanding of corrosion scales, which can be key to structural integrity, employing state-of-the-art approaches to explore their structure/chemistry at the nanoscale. CO2/H2S are primary reagents for internal corrosion of oilfield equipment. Both dissolve in H2O forming acidic solutions, leading to potentially highly corrosive environments (CO2: sweet; H2S: sour). Solid corrosion products may also appear as a consequence of sweet/sour corrosion, with their formation dependent upon a range of parameters, e.g. pH and temperature. If adherent to the carbon steel substrate, such solids can significantly reduce the rate of corrosion, and so are integral to material sustainability. Significant effort has been applied to characterise such established scales, which has resulted in key insights into their nature. Currently, however, there are few nanoscale details about their nucleation, which may be key to their protective properties. For instance, it is generally presumed that CO2-induced scales are formed solely through precipitation subsequent to solution supersaturation, but direct evidence remains elusive. It may be that initial nucleation/growth also involves some other interfacial reaction(s), e.g. through the chemistry of adsorbed CO2-H2O complexes, which have been predicted to be energetically favourable on Fe surfaces.
State-of-the-art characterisation tools will be employed to elucidate interface structure during oilfield scale nucleation. Nuclei morphologies and nucleation sites will be imaged in situ with both electrochemical atomic force microscopy (EC-AFM) and novel transmission electron microscopy cells. The evolution of nuclei crystallinity and size/shape distribution will be observed in situ using synchrotron (DLS beam lines I07/I22), grazing incidence wide angle and small angle X-ray scattering (WAXS/SAXS). High lateral spatial resolution on beam lines I08 and I14 will allow direct insight into interfacial heterogeneity during nucleation, using for example X-ray absorption near edge spectroscopy (XANES) to probe local scale nuclei chemistry.
The outcome of the research will be a nanoscale understanding of oilfield scale nucleation processes that are essential to improving scale protection through early intervention, such as the optimisation of scale nuclei to promote directed growth or the control of scale processes using novel inhibitors.
About BP International Ltd
BP is one of the world’s leading international oil and gas companies. They provide customers with fuel for transportation, energy for heat and light, lubricants to keep engines moving, and the petrochemicals products used to make everyday items as diverse as paints, clothes and packaging. This PhD studentship will be part of the BP International Centre for Advanced Materials (BP-ICAM) community. BP-ICAM brings the full spectrum of academic knowledge under one umbrella, providing the opportunity for collaboration across disciplines. The problems are complex and require an interdisciplinary approach. The practical involvement of BP helps to ensure that ICAM’s innovative research will deliver real-life applications and solutions.
Funding covers tuition fees and annual maintenance payments of £17,000. Students with a first class/2.1 degree (or equivalent) in Engineering, Materials Science, Metallurgy, Physics, Chemistry or another aligned science or engineering subject are encouraged to apply.
Applications will be reviewed as they are received until a candidate is selected; therefore candidates are encouraged to apply early.
Funding is available to UK or EU candidates only.