Fetkovich Oil Deliverability Rate Formula
Fetkovich Oil Deliverability Rate calculates oil flow rate for inflow performance workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (C_f, P_r, P_wf, n_f) are known and the assumptions behind the cited inflow performance 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, q_o equals 957.192894 STB/day.
0.0015
3000
1500
0.85
Inputs
C_f
STB/day/psi^(2n)Fetkovich Performance Coefficient
P_r
psiaAverage Reservoir Pressure
P_wf
psiaFlowing Bottom-Hole Pressure
n_f
dimensionlessFetkovich Flow Exponent
Outputs
q_o
Oil Flow Rate
C_f
Fetkovich Performance Coefficient
delta_p2
Pressure-Squared Drawdown
q_AOF
Absolute Open Flow Rate at Pwf = 0
P_r
Average Reservoir Pressure
P_wf
Flowing Bottom-Hole Pressure
n_f
Fetkovich Flow Exponent
Source and review
reviewedFetkovich, M.J. 1973. The isochronal testing of oil wells; public summaries of Fetkovich IPR equation.
Source