Separation Efficiency of Oil and Water from Oilfield Produced Water Using Cyclonic Flotation

Abstract

To improve the separation efficiency of oil field-produced water, a novel oil-water separation apparatus is developed. The high-efficiency cyclone separation apparatus could meet the continued increase of oil field-produced water and comply with the improvements in emission standards. Effectivity of the self-designed apparatus in oil removal was determined in laboratory and field tests. The effects of inlet flow, oil concentration and aeration amount were determined through laboratory tests. The particle size distribution of the influent and effluent oil-produced water was presented also. Results show that under optimal process conditions, i.e., the inlet flow rate is 2.0 m3/h, imported oil concentration is 1189 mg/L, and aeration rate is 0.6 L/min, effective separation can reach 93.1%. The oil removal rate is generally above 90% and the range of influent concentration is 900–1200 mg/L in the field test. Compared to the traditional oilfield produced water treatment device, the self-designed apparatus can combine both air flotation separation and cyclonic separation. The joint effect of the two kinds of separation, can promote the collision adsorption probability of micro bubbles and oil droplets, and effectively improve the separation efficien