We consider the inverse problem of permeability estimation for two-phase flow in porous media. In the parameter estimation
process we utilize both data from the wells (production data) and spatially distributed data (from time-lapse seismic data).
The problem is solved by approximating the permeability field by a piecewise constant function, where we allow the discontinuity
curves to have arbitrary shape with some forced regularity. To achieve this, we have utilized level set functions to represent
the permeability field and applied an additional total variation regularization. The optimization problem is solved by a variational
augmented Lagrangian approach. A binary level set formulation is used to determine both the curves of discontinuities and
the constant values for each region. We do not need any initial guess for the geometries of the discontinuities, only a reasonable
guess of the constant levels is required.
Keywords Inverse problems - Reservoir description - Parameter identification - Two-phase flow - Level set methods - Augmented Lagrangian optimization - Total variation regularization
Communicated by G. Wittum.