PetrophysicsRock Properties
Raymer-Hunt Transform - Porosity Transit Time Relationship Formula
Raymer-Hunt Transform - Porosity Transit Time Relationship calculates total travel time for rock properties workflows in petrophysics.
How engineers use this formula
Use this formula when the listed inputs (phi, Delta_t_ma, Delta_t_f) 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, Delta_t equals 79.429805 us/ft.
phifraction
0.2
Delta_t_maus/ft
55.5
Delta_t_fus/ft
189
Inputs
phi
fractionPorosity
Delta_t_ma
us/ftMatrix Travel Time
Delta_t_f
us/ftFluid Travel Time
Outputs
Delta_t
us/ft
Total Travel Time
phi
fraction
Porosity
Delta_t_ma
us/ft
Matrix Travel Time
Delta_t_f
us/ft
Fluid Travel Time
Source and review
reviewedBassiouni, Z. 1994. Theory, Measurement, and Interpretation of Well Logs, SPE Textbook Series Vol. 4, Chapter 3, Page 56.
Source