- Shallow geothermal wells: Shallow geothermal wells are typically drilled to depths of less than 500 feet (150 meters). These wells are used for low-temperature applications such as space heating and cooling, and can be found in many residential and commercial buildings.
- Intermediate geothermal wells: Intermediate geothermal wells are drilled to depths of between 500 and 2,000 feet (150 and 600 meters). These wells are used for higher-temperature applications such as power generation and industrial processes.
- Deep geothermal wells: Deep geothermal wells are drilled to depths greater than 2,000 feet (600 meters). These wells are used to access very high-temperature geothermal reservoirs, which are typically found in volcanic regions. Deep geothermal wells are used for power generation and other industrial applications.
The temperature of the geothermal reservoir also plays a role in determining the depth of a geothermal well. The deeper the well, the higher the temperature of the geothermal reservoir. This is because the Earth's temperature increases with depth, due to the decay of radioactive elements in the Earth's crust and the compression of the Earth's materials.
