In this work we consider a principally new statistical approach to the theory of processes of transport in a two-phase condensed environment with randomly distributed non-uniform surface structure. Taking this approach as a base, we considered diffusion in a chaotic porous environment. Such a structure is described with the aid of a curvilinear orthogonal coordinates system natural for geometrical porous surface. The method of averaging the diffusion equation is developed. The equations for average diffused concentration in a porous surface of a solution of ionic components are obtained. These equations take into account the local characteristics of the structure of the environment. In general, this approach is applicable to other equations describing the transport of substance, charge and electromagnetic field in the environment with random interior.