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Capacity Ratio of Hydraulically Fractured Surface Formula

cf=kfWkhc_f=\frac{k_fW}{kh}

Capacity Ratio of Hydraulically Fractured Surface calculates fractured surface capacity ratio for hydraulic fracturing workflows in production engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (k_f, W, k, h) 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, c_f equals 4 dimensionless.

k_fmD

100000

Wft

0.02

kmD

10

hft

50

Inputs

k_f

mD

Fracture Permeability

W

ft

Fracture Thickness

k

mD

Average Formation Permeability

h

ft

Formation Thickness

Outputs

c_f

dimensionless

Fractured Surface Capacity Ratio

k_f

mD

Fracture Permeability

W

ft

Fracture Thickness

Source and review

reviewed

Saydam, T. 1967. Principles of Hydraulic Fracturing. ARI Publishing Co., Page 92.

Source

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