Not speaking to the veracity of the statement but quaise answers this in a different article: "A lot of the challenges are the same as for oil and gas. The subsurface is an uncertain environment. The deeper you go, the more extremes you have, but we've come a long way with the oil and gas industry to develop a whole suite of technologies, techniques and measurement systems to minimise that risk. The main challenge is maintaining wellbores from closing in on themselves as you go deeper. There's a lot of pressure in the rock and these holes eventually will collapse. The way we answer that is by creating a glass wall in the rock as we burn it. When our technology vaporises the rock, it creates a glass wall and that remains on the walls and prevents the hole from collapsing."

https://www.energymonitor.ai/tech/geothermal-can-provide-hal...