We describe the competitive motion of
incompressible immiscible phases within a porous medium as the gradient flow
of a singular energy in the space of nonnegative measures with prescribed
masses, endowed with some tensorial Wasserstein distance. We show the
convergence of the approximation obtained by a minimization scheme á
la R. Jordan, D. Kinderlehrer and F. Otto (SIAM J. Math. Anal.29:1
(1998) 1–17). This allows us to obtain a new existence result for a physically
well-established system of PDEs consisting of the Darcy–Muskat law for each phase,
capillary pressure relations, and a constraint on the volume occupied by the fluid.
Our study does not require the introduction of any global or complementary
pressure.
Keywords
multiphase porous media flows, Wasserstein gradient flows,
constrained parabolic system, minimizing movement scheme