| The general problem of unsteady-state flow phenomena in porous media was considered in this investigation. Emphasis was placed upon the short-time flow characteristics within cylindrical, spherical and linear reservoir geometries, and practical analysis methods were developed for each problem. Additionally, nonlinear unsteady flow behavior in infinite reservoirs was considered. Each solution obtained could optionally be implemented by hand or computer, and several FORTRAN subprograms were also presented.;Solutions for fully developed spherical (or hemispherical, and also linear) flow have not received as much attention in the petroleum literature as have problems posed in cylindrical coordinates (i.e., radial flow). Comprehensive type curve methods for spherical (and linear) flow inclusive of wellbore storage, wellbore phase redistribution and skin effects were proposed in this investigation. Sandface flow analysis with and without phase redistributions in the wellbore were also developed for the three coordinate symmetries studied. A new equation was then derived for estimating the duration of wellbore and near-wellbore effects under spherical or linear flow. Hence this investigation is a step toward the establishment of parity between spherical flow and the companion cylindrical-flow analogue.;At present, the only way to analyze pressure transient data prior to the development of the "semilog straight line" is by type curve matching techniques. However, this study indicated that a reliable new analysis technique may be feasible if bottomhole pressures and sandface flowrates were simultaneously measured during the transitory flow regime. Several case studies were presented to illustrate the field application of this simple new method. |
