A screening model for predicting injection well pressure buildup and plume extent in CO2 geologic storage projects

We present a new screening model for predicting injection well pressure buildup and CO2 plume migration for CO2 geologic sequestration projects. The model requires only limited information and is quite accurate when compared to detailed simulation results. Such models can assist project developers during the early days of project planning (e.g., for 45Q related projects), and also help regulators perform simple checks against detailed numerical models. The screening model consists of two correlations: one for injectivity index in terms of the slope of the CO2 fractional flow curve, and the second for total storage efficiency within the footprint of plume as a function of gravity number and slope of the CO2 fractional flow curve. Using these two correlations, as well as a knowledge of some basic reservoir characteristics and estimates of fluid properties from standard correlations, the injection-well pressure buildup and CO2 plume extent in the formation can be readily estimated. The new correlations show a good match with the results of the underlying simulations, and also provide good agreement with independent calculations for two example problems.