U.S. firm mulls building geothermal power plant from Sidoarjo mudflow
Originally Posted By: Dilli
Normal temperature gradient is 0.1 degree C per every 100 feet. To get down to 180 C they would have to drill @ 4,000 feet. In that area, I think they would have a problem creating a stable well environment given the damage done to the formation already.
Nah, this isn't a temp gradient - remember that the mud is colloids in a water/ steam suspension. The steam is acting as a crude "ejector". Because of depth there is a linear pressure gradient. Drill down 150M and the water in the mud will sit quite happily at 180+C without boiling, but give a vent to this mud, and in the first instance as it rises out of the drill hole there will be a huge release of steam and mud which will then slow down and stabilize as a pressure gradient is established. Dependant on local conditions the mud may be sitting underground at 60C (in the case of Scotland, probably bloody frozen) or in a superheated condition at 600C which is fine until someone take the plug out of the hole then it will desuperheat kicking out huge amounts of energy.