Corrosion & Scaling Mechanisms in Geothermal Environments

With 15,000 employees across 20 countries, Vallourec provides premium tubular solutions for the energy sectors, including oil and gas, as well as emerging energy fields such as geothermal for which Vallourec provides well casings and tubings. Geothermal brines are highly mineralized fluids capable of generating complex corrosion and scaling phenomena, often detrimental to the integrity of these casings/tubings. In the Upper Rhine Graben (URG) in the North-east of France, metallic sulfide scales have been repeatedly observed on low‑alloy steel tubing surfaces and are suspected to contribute to localized degradation under field conditions. Presently, the interplay between metallic sulfide scaling and corrosion in geothermal systems remains poorly understood. Laboratory tests often fail to reproduce field behaviour, suggesting that key environmental parameters are currently overlooked. This PhD project aims to bridge this gap by developing testing methodologies that better replicate the under‑scale corrosion observed during geothermal energy production, and further understanding on the key process variables.

Under the guidance of a highly qualified team of researchers from IFPEN, LaSIE, and Vallourec, the student will undertake the following tasks:

• Characterize real metallic scales from geothermal sites using advanced techniques such as XRD, Raman and FIB-SEM.
• Develop a laboratory setup to reproduce scale formation and corrosion (thermodynamic modelling, controlled precipitation, electrochemistry).
• Identify key parameters governing lab representativity relative to field (e.g. flow, pH, ionic species…).
• Understand localized corrosion mechanisms and assess effect of different metallic grades.

The PhD candidate will be primarily based at IFP energies nouvelles in Solaize, France in a high‑quality work environment within the electrochemistry & materials department. Regular short stays will be carried out at Vallourec in Aulnoye‑Aymeries, France and at LaSIE (Université de La Rochelle), ensuring strong integration within both industrial and academic settings. As a full Vallourec employee, the student will also receive training in metallurgy, steel performance, and geothermal corrosion. The doctoral work will be supervised by an experienced and supportive team across the three institutes, with regular advisory meetings to ensure scientific progress and professional development.

• Master’s degree in chemistry, materials science, or a related field.
• Strong interest in electrochemistry, materials characterization, or aqueous corrosion.
• Some knowledge of thermodynamic modeling (e.g. OLI, PHREEQ-C) is a plus.
• Ability to think critically and solve complex problems, with the organizational capability to work collaboratively across academic and industrial environments.
• Fluent French is preferred, but strong English (C1 level) is a minimum requirement.