Analysis of Plume Extent Using Analytical Solutions for Co2 Storage

The evaluation of possible leakage pathways from CO2 storage operations requires attention to the magnitude, concentration and timescales involved. Herein we discuss a problem related to CO2 storage, the migration of CO2 as it is injected. This is accomplished through the application of analytical solutions. In particular, we derive a new analytical insight into the problem of fluid injection into a confined aquifer, which gives us analytically the furthest extent of the injected fluid (CO2), as well as the extent of the region in which the formation fluid (brine) has evaporated into the injected fluid. We apply these new analytical solutions to a hypothetical injection case based on data from Alberta, Canada, and discuss the results in terms of the surprising variability in observed system responses. We conclude this paper by emphasizing the value of analytical solutions both in semi-analytical frameworks and as benchmarks for numerical simulations.