PetrophysicsRock Properties
Apparent Gamma Ray Recorder Intensity Formula
Apparent Gamma Ray Recorder Intensity calculates apparent recorder intensity for rock properties workflows in petrophysics.
How engineers use this formula
Use this formula when the listed inputs (J_1, J_2, t, r_c) 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, J_at equals 126.61219 counts/s.
J_1counts/s
80
J_2counts/s
140
ts
3
r_cs
2
Inputs
J_1
counts/sInitial Count Rate
J_2
counts/sFinal Count Rate
t
sElapsed Recorder Time
r_c
sRecorder Time Constant
Outputs
J_at
counts/s
Apparent Recorder Intensity
J_1
counts/s
Initial Count Rate
J_2
counts/s
Final Count Rate
t
s
Elapsed Recorder Time
r_c
s
Recorder Time Constant
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 7, Page 148.
Source