Material balance and separator pressure optimization for maximum oil recovery in a production unit

An intermediate pressure, called optimum separator pressure, was determined to maximize the oil API gravity in the stock tank and minimize the Gas/Oil Ratio (GOR) in the Ramshir petroleum production unit in southwestern Iran. The optimum pressure corresponds to a maximum in the API gravity and a minimum GOR. The proposed methodology determined the optimum separator pressure in different stages of separation and consequently production rate increased. The temperature is also important in optimization of production unit operations but the temperature of separation is a function of ambient temperature which is difficult to control. The optimum separator pressures for a 200 m3/h oil production unit were determined. As a result of the optimization performed for this unit, the oil recovery was increased by 2 and 1.5 kg mol/h (about 5 m3/d) during summer and winter seasons, respectively, at the same time improving the quality of crude oil by an increase of 0.2 °API.