Formula No.2 (API units)
PRESSURE GRADIENT (psi/ft)
Mud Density (ppg) x 0.052
For explanation of the formula watch the video below:
You may ask what is the use of finding this pressure gradient. It cannot be just for the sake of it. Pressure gradient can tell many things, like, formation pressure at any depth, mud hydrostatic at any depth and it can be used to tell whether the formation pressure is normal, abnormal or subnormal.
For uses of pressure gradient watch the video below:
EXAMPLE for Formula 2:
Drilling fluid density/ mud weight = 12.0 ppg
Calculate pressure gradient.
Pressure gradient = 12 x 0.052 = 0.624psi/ft
Use this Calculator for Calculating Pressure Gradient using Formula No.2