STORAGE AND UTILIZATION OF CO2 IN PETROLEUM RESERVOIRS - A SIMULATIONSTUDY

There is a growing concern about the effect of greenhouse gases on glo bal temperatures and its consequences. Among many greenhouse gases, ca rbon dioxide produced as a result of fossil fuel burning is a major co ntributor due to the huge volume emitted into the atmosphere. Because fossil fuels remain the driving force of modem economies, any economic growth in the developed or developing countries results in an increas ed emission of carbon dioxide. Consequently, reduction of carbon dioxi de emissions has become an important issue. The Intergovernmental Pane l on Climate Change (IPCC) estimates that a worldwide reduction of the emission of green house gases by more that 60% is necessary to avert' the global climate change. It is now well recognized that the disposa l issue is the most important obstacle to overcome for a practical sol ution of the carbon dioxide problem. In this paper a simulation study on the storage and utilization of carbon dioxide in petroleum reservoi rs has been carried out. For simple storage, simulation studies to det ermine the capacity of a given reservoir are conducted for different r eservoirs with a wide range of governing parameters. Major parameters studied are: initial reservoir pressure, final average reservoir press ure, impurities in the injected gas, petrophysical properties of the r eservoir, and initial fluid saturations. For the utilization, simulati on studies are carried out for both miscible and immiscible flooding e nhanced oil recovery (EOR) processes. It is difficult to maintain carb on dioxide miscibility in a reservoir. It is found that immiscible but stable injection of carbon dioxide may be very effective in recoverin g oil.