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Additional Pressure Drop in the Skin Zone Formula

ΔPskin=141.2QoBoμoSkh\Delta P_{skin} = \frac{141.2 Q_o B_o \mu_o S}{k h}

Additional Pressure Drop in the Skin Zone calculates pressure drop due to skin for well performance workflows in production engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (Q_o, B_o, mu_o, k, h, S) 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, DeltaP_skin equals 169.44 psi.

Q_oSTB/day

500

B_obbl/STB

1.2

mu_ocP

2

kmD

100

hft

50

Sdimensionless

5

Inputs

Q_o

STB/day

Oil Flow Rate

B_o

bbl/STB

Oil Formation Volume Factor

mu_o

cP

Oil Viscosity

k

mD

Reservoir Permeability

h

ft

Reservoir Thickness

S

dimensionless

Skin Factor

Outputs

DeltaP_skin

psi

Pressure Drop Due to Skin

Q_o

STB/day

Oil Flow Rate

B_o

bbl/STB

Oil Formation Volume Factor

mu_o

cP

Oil Viscosity

k

mD

Reservoir Permeability

h

ft

Reservoir Thickness

S

dimensionless

Skin Factor

Source and review

reviewed

Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter 1, Page 37.

Source

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