PetrophysicsElectrical Properties
Apparent Resistivity Formula
Apparent Resistivity calculates apparent resistivity for electrical properties workflows in petrophysics.
How engineers use this formula
Use this formula when the listed inputs (G_t, DeltaV_12, I) 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, R equals 100 ohm m.
G_tm
25
DeltaV_12V
2
IA
0.5
Inputs
G_t
mGeometric Coefficient
DeltaV_12
VPotential Difference Between Two Points
I
ACurrent
Outputs
R
ohm m
Apparent Resistivity
G_t
m
Geometric Coefficient
DeltaV_12
V
Potential Difference Between Two Points
I
A
Current
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 5, Page 93.
Source