The Screening Of Oil Resisting Foaming Agents And Properties Evaluation Of Flooding

This paper is aimed at the crude oil, formation water and formation conditions of No.1Oil Plant of Daqing Oilfield, according to foaming agent properties of interfacial tension andsurface viscosity etc, select foaming agent with high-performance and oil-resistance throughthe molecular structure and the mechanism of oil for foam. The binary foaming oil-displacingsystem which consist of foaming agent, surfactant and polymer, can provide an effectivemethod of oil displacement after polymer flooding.Firstly,10foaming agents with fluorocarbon, anionic and amphoteric surfactants arescreened by the revised method of airflow. The foaming agent was prepared by oilfieldfiltered wastewater and dehydrated crude, of which concentration is0.3%, and its oilsaturation is30%. The results indicate that foaming capability of dodecyl betaine is strongest,fluorocarbon101005take the second place.Secondly，a rate of low-tension surfactant add to binary foam system at limit0.3%totalconcentration of surfactant. The evaluation of the interfacial tension and foaming performanceare done. The results show that, the interfacial tension of binary system which consisted ofdodecyl betaine(0.15%), BS-betaine(0.15%) and HPAM(1500mg/L) are close to the10-2mN/m magnitude. When gas-liquid ratio is1:1, the foam complex index is7800, whichachieve the performance indicators of low-tension foam system.Finally，the selection of polymer concentration and gas-liquid ratio are done. Theresults show that, when the gas-liquid ratio was1:1, oil displacement effect would be best.When gas-liquid ratio is1:1, the concentration of polymer composed foaming system isbetween600mg/L and1200mg/L, the value of enhanced oil recovery is between13.20%and16.28%. To sum up, it is most suitable that the concentration of polymer composed foamingsystem is selected1000mg/L.