Reservoir EngineeringFluid Flow in Porous Media
Steady-State Radial Liquid Productivity Index Formula
Steady-State Radial Liquid Productivity Index calculates productivity index for fluid flow in porous media workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (k, h, mu_o, B_o, r_e, r_w, s) are known and the assumptions behind the cited fluid flow in porous media relationship match the engineering case being checked.
Assumptions
- Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
- The declared units match the field-unit constants used in the formula.
- The cited formula applies to the selected petroleum engineering workflow.
Limitations
- The calculation does not replace a full engineering model or operating procedure.
- Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.
Common mistakes
- Mixing unit systems without converting the inputs.
- Using default example values as field recommendations.
- Applying the formula outside the source assumptions.
Default example
Using the default inputs, J equals 1.471689 STB/day/psi.
kmD
100
hft
50
mu_ocP
2
B_obbl/STB
1.2
r_eft
1000
r_wft
0.328
sdimensionless
2
Inputs
k
mDPermeability
h
ftNet Pay Thickness
mu_o
cPOil Viscosity
B_o
bbl/STBOil Formation Volume Factor
r_e
ftDrainage Radius
r_w
ftWellbore Radius
s
dimensionlessSkin Factor
Outputs
J
STB/day/psi
Productivity Index
Source and review
reviewedLyons, W.C. 2010. Working Guide to Reservoir Engineering. Darcy radial liquid-flow equation.
Source