Huerta, N.J., B.R. Strazisar, S.L. Bryant and M.A. Hesse, “Time-dependent Fluid Migration From a Storage Formation via Leaky Wells” , Energy Procedia, Vol. 63(1), pp. 5724-5736, 2014. DOI: 10.1016/j.egypro.2014.11
A model for the time-dependent flow of CO2-saturated fluid through a leaky well is presented. This simple model accounts for laboratory observations of fracture sealing by secondary precipitation due to complex reactive transport coupling. The model uses the principle of flow in series and a logistic function to describe the evolution of the precipitation zone’s effective permeability as it advects through the domain. A single well leakage scenario is used as an example and to perform a sensitivity study for a range of conditions.
Results show that the initial fracture conductivity, retardation factors, and empirical parameters that describe permeability decrease are the dominant parameters in the model. These parameters determine time to breakthrough of reservoir fluid and amount of fluid leaked at 50 years. For most cases the breakthrough time and total amount leaked are orders of magnitude less than when compared to the constant permeability case. Even when residence time is small (i.e. when leak length is short and aperture is large) the model shows significantly less fluid leaked into an overlying aquifer.
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