Injectivity index: a powerful tool for characterizing CO2 storage reservoirs—a technical note

Injectivity index is a powerful tool that can be easily calculated from field injection and pressure data. Theoretically, injectivity index is linked to reservoir properties such as permeability, thickness of pay, and size of the reservoir. Consequently, injectivity index data can serve as a powerful tool to assess changes in reservoir quality and performance. In this article, we have looked at field data from notable global carbon sequestration projects in order to identify a correlation between injectivity index (J) and the product of reservoir permeability and thickness (kh). Results suggested that there is a linear relationship between J and kh with field data confirming to lower and upper bounds of J = 0.03×kh and J = 0.23×kh respectively. Average trend was calculated to be J = 0.08×kh. This correlative approach can be extremely beneficial when there is a need to estimate pressure buildup corresponding to a target injection or vice versa. The approach can also be used to understand reservoir flowability and performance at a broader scale prior to the need for expensive or time consuming flow and pressure transient testing. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.