1. A digital rock analysis method that comprises: deriving from a pore-matrix model at least one pore structure parameter; determining a distribution of multiple phases within pores of the pore-matrix model; based on said distribution, partitioning the pore-matrix model into multiple phase-matrix models; deriving said at least one pore structure parameter from each of the phase-matrix models; and producing a representation of the at least one pore structure parameter's dependence on said distribution.