Geomechanics and FracturingNaturally Fractured Reservoirs

Matrix Block Shape Factor from Surface Area Formula

\alpha=\frac{A}{V_mx}

Matrix Block Shape Factor from Surface Area calculates matrix block shape factor for naturally fractured reservoirs workflows in geomechanics and fracturing.

Calculate

How engineers use this formula

Use this formula when the listed inputs (A, V_m, x) 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, alpha equals 0.12 1/ft^2.

Aft^2

600

V_mft^3

1000

xft

Inputs

A

ft^2

Matrix Block Surface Area

V_m

ft^3

Matrix Block Volume

x

Characteristic Matrix Block Length

Outputs

alpha

1/ft^2

Matrix Block Shape Factor

A

ft^2

Matrix Block Surface Area

V_m

ft^3

Matrix Block Volume

x

Characteristic Matrix Block Length

Source and review

reviewed

Tiab, D. and Escobar, F.H. 2019. Novel, Integrated and Revolutionary Well Test Interpretation and Analysis, IntechOpen, Equation 6.7.

Source