Screening And Evaluation Of Functional Active Polymer Oil Displacement Agent

In this paper,two kinds of functional polymers QS,SL and one ordinary polymer LD were screened and evaluated under the geological conditions of QHD32-6 reservoir.The microstructures and morphologies of the three flooding agents were studied by elemental analysis,molecular strand size,infrared spectroscopy and scanning electron microscopy.The effects of dissolution time,thickening properties,shear resistance,temperature and salt tolerance,viscoelasticity,adsorption properties,long-term thermal stability,oil-water interfacial tension,emulsification and emulsion stability were evaluated.The effect of three kinds of oil displacement agent on improving oil recovery efficiency were evaluated by heterogeneous cores.The results show that compared with SL and LD,the molecular strand size of QS is the largest and the dissolution time of QS is shortest.It is self-assembled into a space network structure in aqueous solution.The viscoelasticity of QS is best,and the retention rate after shearing and the static adsorption capacity on quartz sand are also very high.The temperature and salt tolerance and long-term thermal stability of QS are better than that of SL and LD.There are surface-active groups that can reduce oil-water interfacial tension and emulsify crude oil to a certain extent in functional active polymers(QS and SL).The activity of QS is stronger than SL and the emulsion between QS and oil is more easily broken when the concentration is low.The experimental results show that QS,SL and LD can improve oil recovery by 19.6%,16.2% and 11.3% respectively at the concentration of 800,1000 and 1500mg/L on the basis of water flooding.Finally,the functional polymer QS is selected as the oil displacement agent.