Tertiary recovery is also known as Enhanced Oil Recovery (EOR) and can allow between a 50% to 80% recovery (as compared to primary recovery which allows 30% recovery). Examples of EOR include thermal methods, gas injection methods, or chemical methods. EOR involves changing the downhole physics to allow a favorable result. Every reservoir contains different parameters, which include geometry, porosity, permeability, relative permeability, fluid properties, etc. By using reservoir modeling, one can simulate different methods of EOR to determine which method is appropriate for the reservoir.