Production EngineeringInjection Wells
Injectivity Index Formula
Injectivity Index calculates injectivity index for injection wells workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (q_i, P_wf, P_r) are known and the assumptions behind the cited injection wells 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, I_i equals 5 bbl/day/psi.
q_ibbl/day
1500
P_wfpsi
1800
P_rpsi
1500
Inputs
q_i
bbl/dayInjection Rate
P_wf
psiBottom-Hole Injection Pressure
P_r
psiAverage Reservoir Pressure
Outputs
I_i
bbl/day/psi
Injectivity Index
q_i
bbl/day
Injection Rate
P_wf
psi
Bottom-Hole Injection Pressure
P_r
psi
Average Reservoir Pressure
Source and review
reviewedStandard injection-well performance definition.
Source