EOR is a technique to increase the production of oil fields other than those that are conventionally used for the oil extraction process. EOR is the third phase that is used for oil recovery after the failure of primary and secondary oil recovery methods. Primary oil recovery is the first stage in the production of hydrocarbons by using natural energy available in the reservoirs such as gas drive, water drive, and gravity drainage. When the natural energy from the reservoirs is depleted, then oil is recovered by secondary recovery methods using an external source such as injection of either natural gas or water. The primary and secondary methods can recover up to 30-40 percent of the hydrocarbons available in the reservoirs.