Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs. Quarterly technical progress report, July 1--September 30, 1995

The objective of this experimental research is to improve the effectiveness of CO{sub 2} flooding in heterogeneous reservoirs. Activities are being conducted in three closely related areas: (1) exploring further the applicability of selective mobility reduction (SMR) in the use of foam flooding, (2) exploring the possibility of higher economic viability of floods at slightly reduced CO{sub 2} injection pressures, and (3) taking advantage of gravitational forces during low interfacial tension (IFT), CO{sub 2} flooding in tight, vertically fractured reservoirs. Additional progress in task 1 has been made in the past quarter in both experimental and analytical directions. A new series assembly of two Berea cores has been made and is currently being investigated, and new and definitive results have been obtained from the parallel experiment, where the authors are studying the effect of capillary contact on foam effectiveness and SMR. Also, during this quarter, a program has been developed to process the results that are generated by the reservoir simulators MASTER and UTCOMP. This is a spreadsheet program containing a series of macros that can be used to plot the flooding performance of a simulation run after it is done. There are converting programs associated with MASTER and UTCOMP so that the results generated by the simulators can be converted into a specific input format to the spreadsheet program. Finally, research continues in two primary areas for task 3: (1) understanding the fundamentals of low interfacial tension behavior via theory and experiment and the influence on multiphase flow behavior and (2) modeling low IFT gravity drainage for application of gas injection in fractured reservoirs