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Thermal Spray Technology Journal Publishes Geo-Drill Paper

Mon, 13 March, 2023

A project paper written by members of the Geo-Drill project consortium has been published by the Journal of Thermal Spray Technology.

Available to view online at, the paper is a, ‘Feasibility Study of High-Velocity Oxy-Fuel (HVOF) Sprayed Cermet and Alloy Coatings for Geothermal Applications.’

The high investment costs and long development cycles has let to geothermal being an underutilised renewable energy source. One of the major challenges for the increased exploitation of geothermal resources is drilling into harsh environments at greater depths, which greatly reduces component lifetimes.

The Geo-Drill consortium have been working on extending component lifetimes through the selection of appropriate coatings, leading to reduced costs and improved drilling efficiencies.

This paper, co-written by Feifei Zhang, Andrew Tabecki, Mike Bennett, Henry Begg, Stefano Lionetti and Shiladitya Paul, investigates the use of high-velocity oxygen fuel (HVOF) spraying for alloy and cermet coatings as well as their performance in a simulated geothermal drilling environment.

The research team have studied a range of coating factors, including surface roughness, thickness, porosity, hardness, adhesion strength, and erosion–corrosion resistance, with the performance compared to selected steels used in geothermal drilling applications.

The paper offers recommendations for the types of HVOF coatings that can potentially be used in geothermal applications, helping to meet the growing global demand for affordable, reliable and sustainable energy.

With Geothermal set to take a larger and more important role in the geothermal mix, Geo-Drill could help improve affordability, opening up new opportunities for this low carbon footprint, ‘always-on,’ renewable energy resource.

You can see the paper, here.


The Geo-Drill project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 815319.