Minimum Air Flux for Fire-Front Advance - Nelson and McNiel Formula
Minimum Air Flux for Fire-Front Advance - Nelson and McNiel calculates minimum air flux required for fire-front advance for waterflooding and eor workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (a_r, E_O2) are known and the assumptions behind the cited waterflooding and eor 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, u_min equals 0.003125 Mscf/ft^2-day.
0.02
0.8
Inputs
a_r
Mscf/ft^3Air required to burn a unit bulk reservoir volume
E_O2
fractionOxygen consumption efficiency
Outputs
u_min
Minimum air flux required for fire-front advance
a_r
Air required to burn a unit bulk reservoir volume
E_O2
Oxygen consumption efficiency
Source and review
reviewedThermal Recovery, Prats, M. (1986)
Prats, M. 1986. Thermal Recovery. Society of Petroleum Engineers, New York, Chapter 8, Page 100.
Source