1. A method for creating an image of an oil, gas, or water reservoir boundary from well pressure test data values comprising: (a) obtaining reservoir pressure response values from a well pressure test selected from the group consisting of drawdown, build-up, fall-off and pulse tests; (b) using the pressure response values obtained to calculate data values reflecting the rate of pressure change over time and the radius of investigation; (c) extracting from the data values obtained in step (b) the response that is due to near-wellbore and matrix effects, to obtain residual values representative of boundary effects; (d) calculating values from the residual values representative of an angle-of-view of the boundary as a function of time; (e) determining values, by analyzing and applying the angle-of-view values obtained in step (d) and the radius of investigation values, indicative of the location and orientation of the boundaries of the reservoir; and (f) forming visual images showing the reservoir boundaries relative to the location of the well, using the values determined in step (e).