Joshi Horizontal Well Productivity Index Formula
Joshi Horizontal Well Productivity Index calculates horizontal well productivity index for well performance workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (k_h, k_v, h, L, A_ac, r_w, mu_o, B_o, s) are known and the assumptions behind the cited well performance 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_h equals 7.506234 STB/day/psi.
100
10
50
1000
40
0.328
2
1.2
0
Inputs
k_h
mDHorizontal Permeability
k_v
mDVertical Permeability
h
ftNet Pay Thickness
L
ftHorizontal Well Length
A_ac
acresDrainage Area
r_w
ftWellbore Radius
mu_o
cPOil Viscosity
B_o
bbl/STBOil Formation Volume Factor
s
dimensionlessSkin Factor
Outputs
J_h
Horizontal Well Productivity Index
A_ft2
Drainage Area
r_eh
Horizontal Drainage Radius
beta
Permeability Anisotropy Coefficient
a_joshi
Semi-Major Axis of Elliptical Drainage Area
R_h
Joshi Horizontal Drainage Ratio
D_joshi
Joshi Productivity Denominator
Source and review
reviewedJoshi, S.D. 1988. Augmentation of Well Productivity With Slant and Horizontal Wells; Petroleum Office horizontal well productivity documentation.
Source