Production EngineeringInflow Performance
Composite IPR Productivity Index Formula
Composite IPR Productivity Index calculates composite ipr productivity index for inflow performance workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (q, P_b, P_wf, P_r) 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, J_i equals 0.407547 STB/day/psi.
qSTB/day
600
P_bpsi
2500
P_wfpsi
1500
P_rpsi
3000
Inputs
q
STB/dayTested Flow Rate
P_b
psiBubble Point Pressure
P_wf
psiFlowing Bottom-Hole Pressure
P_r
psiAverage Reservoir Pressure
Outputs
J_i
STB/day/psi
Composite IPR Productivity Index
q
STB/day
Tested Flow Rate
Source and review
reviewedGuo, B., Lyons, W.C. and Ghalambor, A. 2007. Petroleum Production Engineering: A Computer-Assisted Approach, Page 3/38.
Source