1. A method of interactively deriving and validating a computerized model of a hydrocarbon reservoir with downhole measurements from one or more wells in the earth, comprising: receiving data corresponding to downhole measurements acquired over time at a wellbore of at least one well of interest, and corresponding to flow rates from a plurality of wells including the well of interest; receiving inputs from a user identifying attributes of a hydrocarbon reservoir, the attributes comprising shapes and properties of formation regions, connections between formation regions, and locations of wells into the formation regions; operating a computer to evaluate pressure responses between each of a plurality of wells in the reservoir and the at least one well of interest in the reservoir by solving a fluid flow problem for a structure corresponding to the identified reservoir attributes; operating a computer to superpose the data corresponding to measured flow rates from the plurality of wells to the evaluated pressure responses to calculate a simulated downhole pressure at the at least one well of interest over time; comparing the simulated downhole pressure at the well of interest over time with data corresponding to downhole measurements acquired over time at the at least one well of interest; after the comparing step, receiving inputs from a user modifying the reservoir attributes; and then repeating the operating and comparing steps for the structure corresponding to the modified reservoir attributes.