Geomechanics and FracturingNaturally Fractured Reservoirs

Fracture Storativity Formula

\omega = \frac{\phi_f h_f c_{tf}}{\phi_f h_f c_{tf} + \phi_m h_m c_{tm}}

Fracture Storativity calculates fracture storativity for naturally fractured reservoirs workflows in geomechanics and fracturing.

Calculate

How engineers use this formula

Use this formula when the listed inputs (phi_f, h_f, c_tf, phi_m, h_m, c_tm) are known and the assumptions behind the cited naturally fractured reservoirs 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, omega equals 0.025974 dimensionless.

phi_ffraction

0.1

h_fft

c_tf1/psi

0.00001

phi_mfraction

0.15

h_mft

c_tm1/psi

0.000005

Inputs

phi_f

fraction

Fracture Porosity

h_f

Fracture Thickness

c_tf

1/psi

Total Fracture Compressibility

phi_m

fraction

Matrix Porosity

h_m

Matrix Thickness

c_tm

1/psi

Total Matrix Compressibility

Outputs

omega

dimensionless

Fracture Storativity

phi_f

fraction

Fracture Porosity

h_f

Fracture Thickness

c_tf

1/psi

Total Fracture Compressibility

phi_m

fraction

Matrix Porosity

h_m

Matrix Thickness

c_tm

1/psi

Total Matrix Compressibility

Source and review

reviewed

Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter 1, Page 82.

Source