The start control and final observation problem for a quasi-linear Sobolev type equation

Sufficient solvability conditions of the start control and final observation problem in a weak gener- alized meaning for one abstract quasilinear Sobolev type equation are obtained. Sobolev type equations constitute a large area of nonclassical equations of mathematical physics. Techniques used in this article originated in the theory of semilinear Sobolev type equations. Solvability of the start control and final observation problem for the Barenblatt–Gilman model describing the nonequilibrium countercurrent capillary impregnation was proved on the basis of abstract results. The unknown function corresponds to effective saturation. The main equation of this model is nonlinear and implicit with respect to the time derivative which makes it quite difficult to study. Formulation of this problem agrees with consideration of the effect of disequilibrium, which is the characteristic feature of the considered model.