An experimental investigation has been carried out using surfactant solutions to displace Nubia crude oil (October field). The effect of surfactant concentration and slug size has been investigated. The effect of oil saturation at the start of surfactant injection is also studied. The results indicate that the oil recovery factor increases with increasing the oil saturation at the start of surfactant injection. The maximum surfactant recoverability is obtained by a slug size of 10% of the pore volume with 5000 ppm surfactant concentration. It is also found that the oil recovery factor obtained by a small slug size with a high surfactant concentration is higher than that resulted by a big slug size with a lower surfactant concentration.