PetroCalcHubFree
Production EngineeringHydraulic Fracturing

Equivalent Skin Factor in Fractured Wells Formula

Sf=0.7ln(xfrw)S_f = 0.7 - \ln\left(\frac{x_f}{r_w}\right)

Equivalent Skin Factor in Fractured Wells calculates equivalent fracture skin factor for hydraulic fracturing workflows in production engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (x_f, r_w) are known and the assumptions behind the cited hydraulic fracturing 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_f equals -5.291465 dimensionless.

x_fft

100

r_wft

0.25

Inputs

x_f

ft

Fracture Half Length

r_w

ft

Wellbore Radius

Outputs

S_f

dimensionless

Equivalent Fracture Skin Factor

x_f

ft

Fracture Half Length

r_w

ft

Wellbore Radius

Source and review

reviewed

Guo, B., Lyons, W.C. and Ghalambor, A. 2007. Petroleum Production Engineering: A Computer-Assisted Approach, Page 17/257.

Source

Related formulas and calculators

Productivity Index and Straight-Line IPR
Inflow Performance
Vogel Inflow Performance Relationship
Inflow Performance
Rawlins-Schellhardt Gas Deliverability Rate
Inflow Performance
Gas Deliverability Pressure-Squared Drawdown
Inflow Performance
Rawlins-Schellhardt Absolute Open Flow Potential
Inflow Performance
Rawlins-Schellhardt Deliverability Coefficient from Test Point
Inflow Performance