Production EngineeringWell Performance
Perforation Skin Factor Formula
Perforation Skin Factor calculates perforation skin for well performance workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (s_H, s_v, s_wb, s_pd) 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_p equals 4.9 dimensionless.
s_Hdimensionless
1.2
s_vdimensionless
0.8
s_wbdimensionless
0.4
s_pddimensionless
2.5
Inputs
s_H
dimensionlessHorizontal or Plane Flow Skin
s_v
dimensionlessVertical or Converging Flow Skin
s_wb
dimensionlessWellbore Effect Skin
s_pd
dimensionlessDamaged Zone Skin around Perforation
Outputs
s_p
dimensionless
Perforation Skin
s_pd
dimensionless
Damaged Zone Skin around Perforation
Source and review
reviewedBell, W.T., Sukup, R.A. and Tariq, S.M. 1995. Perforating, Henry L. Doherty Memorial Fund of AIME, Society of Petroleum Engineers, Page 65.
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)
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Effective Wellbore Radius of a Horizontal Well – van der Vlis et al. Method
Well Performance