Reservoir EngineeringWell Performance
Effective Wellbore Radius of a Horizontal Well – Method 1 (Anisotropic Reservoirs) Formula
Effective Wellbore Radius of a Horizontal Well – Method 1 (Anisotropic Reservoirs) calculates effective wellbore radius for well performance workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (A, L, k_h, k_v, 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 111.569605 ft.
Aacres
40
Lft
1000
k_hmd
100
k_vmd
10
hft
50
r_wft
0.5
Inputs
A
acresDrainage Area
L
ftLength of Horizontal Well
k_h
mdHorizontal Permeability
k_v
mdVertical Permeability
h
ftReservoir Thickness
r_w
ftWellbore Radius
Outputs
r_eh
intermediateft
Radial Equivalent Drainage Radius
a
intermediateft
Dimensionless Length Parameter
beta
intermediatedimensionless
Anisotropy Ratio
r_wd
ft
Effective Wellbore Radius
Source and review
reviewedHorizontal Well Technology, Joshi, Page: 90.
Source