A method for evaluating portions of a reservoir includes classifying producing reservoir portions in the reservoir into multiple classifications based on production data associated with the producing reservoir portions. Each classification corresponds to a range of the production data. The method further includes generating a correlation between the classifications of the producing reservoir portions to a petrophysical property and elastic property of the subterranean formation, generating, based on the correlation, a spatial distribution function of reservoir quality to represent predicted classifications as a function of physical locations in the reservoir, and evaluating, using the spatial distribution function, a physical location in the reservoir for reservoir quality.