Just to clarify, neither of those projects (2006 and 2013) was done by Fervo. Fervo wasn't even founded until 2017.
The Basel project caused earthquakes because it used a single, vertical well to pump high-pressure water into dense granite all at once, which accidentally over-pressurized and lubricated a major existing fault line. In St. Gallen, the earthquake happened when drillers unexpectedly hit a high-pressure methane gas pocket. The rapid injection of heavy drilling mud used to control the gas kick built up intense, localized pressure that triggered a nearby fault.
Fervo's modern method avoids these issues by using horizontal drilling to distribute fluid pressure gently across miles of rock rather than spiking it in one spot. They also use advanced fiber-optic cables for real-time micro-seismic monitoring, allowing them to sense tiny rock movements and adjust fluid rates instantly before a felt earthquake can ever develop.
The Basel project caused earthquakes because it used a single, vertical well to pump high-pressure water into dense granite all at once, which accidentally over-pressurized and lubricated a major existing fault line. In St. Gallen, the earthquake happened when drillers unexpectedly hit a high-pressure methane gas pocket. The rapid injection of heavy drilling mud used to control the gas kick built up intense, localized pressure that triggered a nearby fault.
Fervo's modern method avoids these issues by using horizontal drilling to distribute fluid pressure gently across miles of rock rather than spiking it in one spot. They also use advanced fiber-optic cables for real-time micro-seismic monitoring, allowing them to sense tiny rock movements and adjust fluid rates instantly before a felt earthquake can ever develop.