Improvement Of Reservoir Studies Through Use Of Two-Dimensional Mathematical Analysis

Publication Rights Reserved Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and considered for publication in one of the two SPE magazines with the paper. This paper illustrates the many types of reservoir predictions which can be made using two-dimensional analyses. These advanced techniques will enable engineers to improve reservoir predictions; and more accurate predictions will, of course, provide a better basis for management decisions. Specifically, the two-dimensional techniques have proved valuable in predicting the following types of reservoir behavior:Irregular advance of gas or water and its arrival time at specific reservoir locations.Gas overriding or water underrunning oil.Cross flow between reservoir layers and water imbibition into tight layers and lenses or from a fracture into a matrixblock.The coning tendencies of a single well.The saturation distribution behind a front. Examples of these types of behavior presented in this paper are: a detailed study of a large gas injection project; pattern waterflood studies of both 5-spot and modified 9-spot patterns; and a study of oil recovery by imbibition from a fracture matrix system. These studies were made using a two-dimensional, two-phase, immiscible fluid-flow analysis that considers viscous, gravitational, and capillary forces. Also shown is a recent comparison of the observed and mathematically predicted behavior of a laboratory model. This provides additional verification of the mathematical techniques. Introduction Most reservoir studies are made to compare various methods of reservoir depletion and to aid management in determining optimum development or operation of an oil field.