Reservoir EngineeringWell Performance
Joshi Isotropic Horizontal Well Effective Radius Formula
Joshi Isotropic Horizontal Well Effective Radius calculates effective wellbore radius of horizontal well for well performance workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (A, L, h, r_w) 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, r_wd equals 721.784886 ft.
Aacre
160
Lft
2000
hft
50
r_wft
0.328
Inputs
A
acreDrainage Area
L
ftHorizontal Well Length
h
ftReservoir Thickness
r_w
ftWellbore Radius
Outputs
r_wd
ft
Effective Wellbore Radius of Horizontal Well
r_eh
intermediateft
Equivalent Horizontal Drainage Radius
a_joshi
intermediateft
Major Half-Axis of Drainage Ellipse
Source and review
reviewedJoshi, S.D. Horizontal Well Technology, Page 90.
Source