Definition - What does Geothermal Gradient mean?
Geothermal gradient is related to temperature values with respect to the depth. This means that as one goes deep down the Earth’s surface, the rate of temperature increases. Because of this reason, there is high temperature at certain depth in an oil or gas well. Geothermal gradient is measured in K/m (or Kelvin per meter). This is its SI unit of measurement.
Petropedia explains Geothermal Gradient
As one goes deep down the earth surface, the internal temperature increases and after certain depth the temperature becomes very high. This happens because of geothermal gradient. Geothermal gradient is known by various names and it is also called as “Thermal Gradient” or “Temperature Gradient”. Geothermal or Thermal or Temperature gradient is measured per 100 feet of the depth and is measured in either Degree Celsius or Fahrenheit. Geothermal gradient is a vector quantity and is represented as ratio of difference in temperature at two locations and the distance between them.
Thus, Geothermal Gradient (dT) is equal to dt/dL
Where, dt represents temperature values at two or more different locations and dL represents distance at which these different locations are apart from each other (in meters or feet)