A Semi‐Analytical Solution to Evaluate the Spatiotemporal Behavior of Diffusive Pressure Plume and Leakage From Geological Storage Sites
Ayon Kumar Das, Hassan Hassanzadeh
Abstract
Abstract Analytical and semi‐analytical approaches provide an easy‐to‐use tool to verify the success of long‐term and large‐scale deployment of subsurface CO 2 storage. Existing classical solutions lack significant features that are essential in the interpretation of the spatiotemporal evolution of pressure plume. We, obviating the limiting assumptions, report a novel general semi‐analytical solution to a physical problem where a storage layer and a caprock are embedded in an infinite medium. We exploited the features of an integral transform technique and Laplace transform to derive the new solution. An effective numerical treatment is suggested to evaluate the obtained solutions. We identify a distorted Gaussian spatiotemporal pressure plume for the cases when the overburden/underburden permeabilities are less than that of the storage layer. We investigate the nature of temporal behavior of leakage rates and identify a scaling relation in the form of L d ∝ t d 1 /2 for dimensionless leakage rate and time. We also present a benchmark pressure trend to detect the pressure anomaly signaling potential brine and CO 2 leakage. This theory will be invoked as a benchmark analytical study in fields where diffusion is of immense interest.