Pore Pressure Gradient
Definition - What does Pore Pressure Gradient mean?
Pore Pressure Gradient is the change in pressure per unit depth. It is measured in kPa/m (kilo Pascal per meter) or psi/ft. Pore Pressure Gradient for oil and gas wells can be calculated as follows:
P = 0.052 * mud weight * true vertical depth.
Mud weight is in pounds per U.S. gallons
True vertical depth (TVD) is in feet.
0.52 is the result of using dimensional analysis.
Petropedia explains Pore Pressure Gradient
Drilling Engineers use Pore Pressure Gradient during the process of drilling oil and gas wells. During drilling procedure, Pore Pressure Gradient is expressed as a gradient in relation to the depth. It is defined in API type IADC (International Association of Drilling contractors) physical units of measurement generally in "psi per foot". As we go down the well, the pressure inside it increases. The following are the few methods which are used for determining pore pressure:
- Ratio Method
- Eaton’s Method
- Effective Stress Method
- Sonic Method
- Equivalent Depth Method
- Resistivity method