Heated-Zone Oil Recovery from Air-Oil Ratio Formula
Heated-Zone Oil Recovery from Air-Oil Ratio calculates heated-zone oil recovery fraction for waterflooding and eor workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (a_r, F_air, phi, E_O2, S_oi, S_of) 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, E_cb equals 0.701875 fraction.
0.02
2
0.25
0.8
0.65
0.25
Inputs
a_r
Mscf/ft^3Air Required to Burn Unit Reservoir Volume
F_air
Mscf/bblAir Injected per Unit Oil Produced
phi
fractionPorosity
E_O2
fractionOxygen Consumption Efficiency
S_oi
fractionInitial Oil Saturation
S_of
fractionOil Saturation After Burning
Outputs
E_cb
Heated-Zone Oil Recovery Fraction
a_r
Air Required to Burn Unit Reservoir Volume
F_air
Air Injected per Unit Oil Produced
E_O2
Oxygen Consumption Efficiency
S_oi
Initial Oil Saturation
S_of
Oil Saturation After Burning
Source and review
reviewedThermal Recovery, Prats, M. (1986)
Prats, M. 1986. Thermal Recovery. Society of Petroleum Engineers, Chapter 8, Page 104.
Source