PetrophysicsRock Properties
Fresh Water-Filled Porosity - Limestones Formula
Fresh Water-Filled Porosity - Limestones calculates water-filled porosity for rock properties workflows in petrophysics.
How engineers use this formula
Use this formula when the listed inputs (rho_b, rho_ls, rho_w) are known and the assumptions behind the cited rock properties 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, Phi equals 0.181287 fraction.
rho_bg/cm^3
2.4
rho_lsg/cm^3
2.71
rho_wg/cm^3
1
Inputs
rho_b
g/cm^3Bulk Density
rho_ls
g/cm^3Limestone Density
rho_w
g/cm^3Water Density
Outputs
Phi
fraction
Water-Filled Porosity
rho_b
g/cm^3
Bulk Density
rho_ls
g/cm^3
Limestone Density
rho_w
g/cm^3
Water Density
Source and review
reviewedBassiouni, Z. 1994. Theory, Measurement, and Interpretation of Well Logs, SPE Textbook Series Vol. 4, Chapter 8, Page 164.
Source