A system and a method for estimating a reservoir parameter are provided. The method includes calculating a plurality of priors using a Markov random field, the plurality of priors comprising probability distributions of a plurality of litho-types; calculating posterior distributions based on the priors, the posterior distribution depending upon measured geophysical data, geophysical attributes and reservoir parameters; and determining at least a portion of litho-types in the plurality of litho-types that correlate most with the measured geophysical data.