This won’t work until they figure out how to drill two holes that meet, so they can pump water down one hole, and have steam come out the other. Failure means more underground explosions and earthquakes.
I saw a show a couple of weeks ago on either the Discovery or Science Channels. It covered how Iceland is doing this already. According to the show, they used only one pipe, though it was fairly vague on the whole subject.
Of course, Iceland’s heat source is much closer to the surface than these guys are talking about.
Don't need two holes. You have a tubing and a Casing. The casing is the outer part, tubing being a smaller diameter pipe inside the casing. Pump water down the tubing, capture it as steam at the top of the casing.