Electrokinetic Potential Across Mud Cake Formula
Electrokinetic Potential Across Mud Cake calculates electrokinetic potential for electrical properties workflows in petrophysics.
How engineers use this formula
Use this formula when the listed inputs (x_mud, p, y_mud) are known and the assumptions behind the cited electrical 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, E_k equals 0.28854 V.
0.002
500
0.8
Inputs
x_mud
dimensionlessMud-Composition Empirical Constant
p
psiDifferential Pressure Across Mud Cake
y_mud
dimensionlessMud-Resistivity Empirical Exponent
Outputs
E_k
Electrokinetic Potential
x_mud
Mud-Composition Empirical Constant
p
Differential Pressure Across Mud Cake
y_mud
Mud-Resistivity Empirical Exponent
Source and review
reviewedTheory, Measurement, and Interpretation of Well Logs, Bassiouni, Z. (1994)
Bassiouni, Z. 1994. Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4, Chapter 6, Page 131.