Abstract
Abstract
This paper covers theoretical research on pulse propagation in linear cores saturated with air, and propagation in linear cores saturated with air, and discusses bow pulse tests in these systems can be analyzed to provide a measure of the porosity and permeability of the porous medium. It also covers permeability of the porous medium. It also covers experimental work designed to compare these properties, as calculated from pulse-test data, with properties, as calculated from pulse-test data, with those determined by conventional measurements. The paper shows that, when such pulse data are analyzed correctly, the comparison is very favorable; i.e., permeability values vary no more than 3 percent and porosity values no more than 0.5 percent. We conclude that pulse experiments with linear cores saturated with air give data, which when analyzed by methods based on the diffusion equation, give permeability and porosity values comparable with permeability and porosity values comparable with those obtained by conventional methods.
Introduction
Pulse testing is a recently developed method for evaluating reservoir storage capacity and fluid transmissibility. Papers have described the basic theory, based on the diffusion equation, and techniques of pulse testing as applied to field operations. Although some of the papers describe field applications, none report laboratory experimental investigations of pulse testing. This paper covers experimental and theoretical research on pulse propagation through porous media. It tests the adequacy of the use of the diffusion equation as a basis for interpreting pulse-test data.
Using the diffusion equation, the theory of pulse propagation in a linear porous system and a method propagation in a linear porous system and a method of interpreting the experimental data are derived. A few experiments conducted on long Berea cores saturated with air are described. The porosity and permeability values were determined by gas expansion permeability values were determined by gas expansion and steady-state flow, respectively, and the values were compared with those theoretically calculated from experimental pulse data. The comparison shows that the values determined by the conventional methods compare well with those calculated from the pulse data.