Earthquakes Induced by Fluid Injection - 7 of 9
Earthquakes Induced by Fluid Injection FAQs - 9 Found
To produce natural gas from shale formations, it is necessary to increase the interconnectedness of the pore space (permeability) of the shale so that the gas can flow through the rock mass and be extracted through production wells. This is usually done by hydraulic fracturing ("fracking"). Fracking causes extremely small earthquakes, but they are almost always too small to be a safety concern. In addition to natural gas, fracking fluids and salt water trapped in the same formation as the gas are returned to the surface. These wastewaters are frequently disposed of by injection into deep wells. The injection of wastewater and salt water into the subsurface can cause earthquakes that are large enough to be felt and may cause damage.