Abstract: An improved method is provided for establishing the location and orientation of the boundaries surrounding a reservoir and creating an image thereof. A conventional well test is performed on a well, establishing measures of the well's pressure response as a function of the rate of pressure change in the reservoir over time. Conventional techniques may be used to determine measures of the radius of investigation. A plurality of radii of investigation are determined as a function of time. A calculated response for an infinite and radially extending well are the measured response are compared as a ratio. Variation of the ratio from unity is indicative of the presence of a boundary at that radius of investigation and the magnitude of its effect related to an angle-of-view. Each radius of investigation is deemed analogous to a ring. Reservoir encompassed by this ring is in communication with the well.

Abstract: A method is provided for establishing the location and orientation of the boundaries surrounding a subterranean reservoir and creating an image thereof. A conventional pressure test is performed on a well, establishing measures of the well's pressure response as defined by the rate of pressure change in the reservoir over time. Conventional techniques are used to determine measures of the radius of investigation. A calculated response for an infinite and radially extending well and the measured response are compared as a ratio. Variation of the ratio from unity is indicative of the presence of a boundary and its magnitude is related to an angle-of-view. The angle-of-view is related to the orientation of the boundary to the well. By combining the angle-of-view and the radius of investigation, one can define vectors which extend from the well to locations on the boundary, thereby defining an image of the boundary.