Production EngineeringWell Performance
Skin Factor from Damaged Zone Permeability Formula
Skin Factor from Damaged Zone Permeability calculates skin factor for well performance workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (k, k_s, r_s, 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, s equals 2.079442 dimensionless.
kmD
100
k_smD
50
r_sft
2
r_wft
0.25
Inputs
k
mDReservoir Permeability
k_s
mDDamaged Zone Permeability
r_s
ftRadius of Damaged Zone
r_w
ftWellbore Radius
Outputs
s
dimensionless
Skin Factor
k
mD
Reservoir Permeability
k_s
mD
Damaged Zone Permeability
r_s
ft
Radius of Damaged Zone
r_w
ft
Wellbore Radius
Source and review
reviewedTowler, B.F. Fundamental Principles of Reservoir Engineering, Page 62.
SourceRelated formulas and calculators
Effective Wellbore Radius of a Well in Presence of Uniform Flux Fractures
Well Performance
Effective Wellbore Radius of a Horizontal Well – Method 1 (Anisotropic Reservoirs)
Well Performance
Effective Wellbore Radius of a Horizontal Well – van der Vlis et al. Method
Well Performance