A methodology for forecasting carbon dioxide flooding performance

Abstract

A methodology was developed for forecasting carbon dioxide (CO2) flooding performance quickly and reliably. The feasibility of carbon dioxide flooding in the Dollarhide Clearfork "AB" Unit was evaluated using the methodology. This technique is very helpful when time and data resources are limited. The methodology consists of five tasks: 1) select a section of the reservoir with the most detailed geologic, reservoir, and production data, 2) perform material balance analysis for the selected section to determine 001? and the history of total expansion, voidage, and injectage, 3) establish an average 5-spot pattern within the selected section, 4) develop a black oil numerical simulation model for a quarter of the 5-spot pattern and simulate the primary and waterflood recovery processes, and 5) forecast carbon dioxide performance using Shell's Scoping model, Texaco's "PROPHET" model, and VIP miscible simulator. One of the major limitations of the methodology is that details of individual well performance and reservoir pressure and fluid saturation distributions in the project area are not available. Therefore, the forecast is limited to the average pattern and to the reservoir as a whole. Results of the Dollarhide Clearfork simulation study show that 9.7 % to 14.1 % of OOIP may be recovered by C02 flood in the selected section. It would require WAG injection cycles with a total fluid injection of 0.831 HCPV.