Development of skid CO₂ pressurized injection plant and its application in oil recovery enhancement

After two decades of Jiangsu Province is confronted production, the complicated fault-block oilfield of Qintong Sag in North with difficulty of oil recovery enhancement. Based on the field's characteristics that it is located in water region and rich in CO₂, the skid CO₂ pressurized injection plant is developed. The plant is comprised of surge tank, injection pump and heat exchanger, all of them are placed on a mobile skid, and CO₂ is directly transported to well site by gas carrier. After using the skid CO₂ pressurized injection plant and its matching techniques, 4 490 _t CO₂ had been cumulatively injected, 10 724 _t crude oil had been cumulatively increased, the average oil draining rate by CO₂ had been 2.39 _t on oil for per ton CO₂, its success ratio reached 100% and the input/output ratio was 1:2.04 by the end of 2004. The field applications show that the plant has the advantages of low transportation fee, high speed, good flexibility, and good adaptability, which meet the requirements of oil recovery enhancement.