We present a method to obtain a 2D description of a reservoir in terms of transmissivity and diffusivity estimated from well testing. This technique is based on the averaging of the parameters in a proposed interference-test measurement area. This area depends on time, diffusivity, and pressure-gauge sensitivity. We discuss a field application in a heterogeneous, anisotropic reservoir, and we use a simulator that uses oiVwater production data from a pilot water-injection test to validate the application's results. 2132200 2130100 • 4 ( I J \ / I / • 12 r...--, / \ / / J J / / /