A method for modeling a reservoir includes receiving vertical formation data describing geological formations in a vertical direction as a function of vertical depth, receiving near-wellbore horizontal formation data describing the geological formations in a horizontal or deviated direction near a wellbore up to a wellbore instrument range, correlating the vertical formation data with the near-wellbore horizontal formation data to create horizontally adjusted formation data to describe the geological formations in the vertical direction beyond the wellbore instrument range, along the horizontal or deviated direction, receiving hydraulic fracture geometry data that describes actual hydraulic fracture geometry, and limiting a described geometry of the geological formations to the actual hydraulic fracture geometry to provide an accurate estimation of usable reservoir.