Henry Begg, TWI Ltd

Solutions to Materials Challenges in Geothermal

• Underused compared with other renewables, despite global abundance

• Need high enthalpy reservoir

• Geologically active parts of the world

• Deep drilling

Geothermal – free power beneath our feet?

Why isn’t it everywhere?

• Projects require large capital outlay

• Drilling

• Plant

What’s holding us back from building plant?

Cost

The projects have received funding from the European Union’s Horizon 2020 program under grant agreement numbers 815319 and 764086

• Significant materials challenges

• Wear/fracture of drill components in breaking rock

• Associated down-time with removing the drill string

• Wear of components in transport of cuttings

Why is drilling so expensive?

Damaged drill bit – Dexcel (Wikipedia)

• Significant materials challenges

• Wear/fracture of drill components in breaking rock

• Associated down-time with removing the drill string

• Wear of components in transport of cuttings

Why is drilling so expensive?

Worn drill component - Image courtesy of the GeoDrill consortium

This project received funding from the European Union’s Horizon 2020 program under grant agreement number 815319.

• New materials & coatings

• GO-WC

• Hardfacing HVOF and High Entropy Alloys

• Novel diffusion bonding techniques

• New hammer design

• Fewer moving parts – bi-stable fluidic oscillator

• Intelligent monitoring system

• 3D printed sensors directly on drill string components

HVOF coating – copyright TWI Ltd

• Significant materials challenges

• Corrosion – aggressive geochemistry (temperature, pH, chloride, H2S)

• Erosion – suspended, precipitated solids cause wear

• Scaling – precipitation of dissolved minerals

Why is plant so expensive?

Corroded component –Image courtesy of the GeoCoat consortium

• Significant materials challenges

• Corrosion – aggressive geochemistry (temperature, pH, chloride, H2S)

• Erosion – suspended, precipitated solids cause wear

• Scaling – precipitation of dissolved minerals

Why is plant so expensive?

Eroded component - Image courtesy of the GeoCoat consortium

• Significant materials challenges

• Corrosion – aggressive geochemistry (temperature, pH, chloride, H2S)

• Erosion – suspended, precipitated solids cause wear

• Scaling – precipitation of dissolved minerals

Why is plant so expensive?

Boch, Ronny & Szanyi, János & Leis, Albrecht & Mindszenty, A & Deák, József & Kluge, Tobias & Hippler, Dorothee & Demény, Attila & Dietzel, Martin. (2016). Geothermal Carbonate Scaling: Forensic Studies

Applying High-Resolution Geochemical Methods. Proceedings of the European Geothermal Congress. ISBN: 978-2-9601946-0-9. S-GC.

This project received funding from the European Union’s Horizon 2020 program under grant agreement number 764086.

• New coatings

• New compositions (high entropy alloys, Ni-PTFE composites)

• Range of deposition techniques (HVOF, laser cladding, electroless plating, esd)

• New materials

• Novel metal matrix composites Laser cladding – copyright TWI Ltd

Contact Details

Henry Begg

Section Manager

Surface Engineering

TWI Ltd

tel: +44 1223 899 565

email: henry.begg@twi.co.uk

web: www.twi-global.com