Production EngineeringInflow Performance
Horizontal Well Fetkovich IPR Rate Formula
Horizontal Well Fetkovich IPR Rate calculates oil flow rate for inflow performance workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (q_omax, P_wf, P_r, n) 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 794.417881 STB/day.
q_omaxSTB/day
1000
P_wfpsi
1500
P_rpsi
3000
ndimensionless
0.8
Inputs
q_omax
STB/dayMaximum Oil Rate at Maximum Drawdown
P_wf
psiFlowing Bottom-Hole Pressure
P_r
psiShut-In or Average Reservoir Pressure
n
dimensionlessFetkovich Exponent
Outputs
q_o
STB/day
Oil Flow Rate
q_omax
STB/day
Maximum Oil Rate at Maximum Drawdown
P_wf
psi
Flowing Bottom-Hole Pressure
P_r
psi
Shut-In or Average Reservoir Pressure
Source and review
reviewedJoshi, S.D. 1991. Horizontal Well Technology. PennWell Publishing Company, Chapter 7, Page 240.
Source