Petrospec Technologies
Pore Pressure / Fracture Gradient Worksheet
PP = obg - (obg - nhg) * (val
o
/ val
n
)
EE
FG = PP + (obg - PP) * poi / (1 - poi)
Constants
Constant Name
Value
Overburden Gradient (psi/ft)
Normal Hydrostatic Gradient (psi/ft)
Equation Exponent
Conductivity = -1.2
Resistivity = 1.2
Sonic = -3.0
Velocity = 3.0
Data Values
True Vertical Depth
(feet)
Observed Log Value
Normal Log Value
Pore Pressure
(psi/ft)
Fracture Gradient
(psi/ft)
