Enter the injection rate and pressure drop across the injection interval into the calculator to determine the Injectivity Index. This calculator can also evaluate any of the variables given the others are known.

## Injectivity Index Formula

The following formula is used to calculate the Injectivity Index.

II = Q / ΔP

Variables:

- II is the Injectivity Index (bbl/psi)
- Q is the injection rate (bbl/day)
- ΔP is the pressure drop across the injection interval (psi)

To calculate the Injectivity Index, divide the injection rate by the pressure drop across the injection interval. The result is the Injectivity Index, which measures the efficiency of fluid injection into a reservoir.

## What is an Injectivity Index?

The Injectivity Index is a measure used in the field of petroleum engineering to determine the efficiency of fluid injection into a reservoir. It is calculated by dividing the injection rate by the pressure difference between the injection pressure and the reservoir pressure. A higher injectivity index indicates a more efficient injection process, which can lead to increased oil recovery. This index is crucial in the design and optimization of enhanced oil recovery projects.

## How to Calculate Injectivity Index?

The following steps outline how to calculate the Injectivity Index.

- First, determine the injection rate (Q) in barrels per day (bbl/day).
- Next, determine the pressure drop across the injection interval (ΔP) in pounds per square inch (psi).
- Next, gather the formula from above = II = Q / ΔP.
- Finally, calculate the Injectivity Index.
- After inserting the variables and calculating the result, check your answer with the calculator above.

**Example Problem : **

Use the following variables as an example problem to test your knowledge.

injection rate (Q) = 120 bbl/day

pressure drop across the injection interval (ΔP) = 50 psi