Granite tests find record permeability

In England, exploratory drilling in Weardale, County Durham by Scientists from Newcastle University found record levels of permeability in granite, which is important for geothermal applications, as heat is extracted by pumping working fluids into the rock and drawing it back up again. Granite can be particularly useful as it can be rich in radioactive elements that generate heat as they decay. The results were obtained by pumping naturally-occurring saline groundwater from an exploratory borehole and monitoring the change in water levels. A permeability of almost 200 darcies was recorded, which is far higher than most prolific oil and gas reservoirs. The scientists believe the find is not unique to the Weardale granite, as there are similar granites worldwide which may display equally high levels of permeability.