PetrophysicsRock Properties
Electron Density Index for Gamma-Gamma Absorption Logging Formula
Electron Density Index for Gamma-Gamma Absorption Logging calculates electron density index for rock properties workflows in petrophysics.
How engineers use this formula
Use this formula when the listed inputs (N_e, N_A) 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, rho_e equals 1,000 mol/m^3.
N_e1/m^3
3.01107038e26
N_A1/mol
6.02214076e23
Inputs
N_e
1/m^3Number of Electrons per Unit Volume
N_A
1/molAvogadro Constant
Outputs
rho_e
mol/m^3
Electron Density Index
N_e
1/m^3
Number of Electrons per Unit Volume
Source and review
reviewedBassiouni, Z. 1994. Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4, Chapter 2, Page 36.
Source