Reservoir EngineeringWell Performance
Joshi Horizontal Well Drainage Ellipse Area Formula
Joshi Horizontal Well Drainage Ellipse Area calculates horizontal well drainage area for well performance workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (r_eh, k_h, k_v) 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, A_ac equals 22.806676 acres.
r_ehft
1000
k_hmD
100
k_vmD
10
Inputs
r_eh
ftHorizontal Drainage Radius
k_h
mDHorizontal Permeability
k_v
mDVertical Permeability
Outputs
A_ac
acres
Horizontal Well Drainage Area
A_ft2
ft2
Horizontal Well Drainage Area
r_ev
ft
Vertical-Plane Equivalent Drainage Radius
beta
dimensionless
Permeability Anisotropy Coefficient
Source and review
reviewedJoshi, S.D. 1988. Augmentation of Well Productivity With Slant and Horizontal Wells; Petroleum Office horizontal well drainage-area documentation.
Source