Study on Performance and Mechanism of Compound Polymer Flooding in Honggang Oilfield

Chemical flooding is suitable in Block 113-3 of Honggang Oilfield because the reservoirs in this field are characterized by thick layers, high average permeability and the serious interlayer heterogeneity. To meet the actual requirments for development of Block 113-3 of Honggang Oilfield, a series of experiments have been conducted to evaluate the viscosifying, salt tolerance, temperature and shear resistance, stability, rheological property and viscoelasticity characteristics of the compound polymers and common polymers. The study results indicated that comparing with the common polymer, the compound polymers are better in propreties of the viscosifying, salt tolerance, temperature and shear resistance, and the the distribution of the relative molecular mass is also wider. The compound polymers are better in compatibility with the reservoirs because the resistance factor and residual resistance factor are larger, and swept volume is also larger. Therefore, it is recommendated that compound polymer flooding should be used in Block 113-3 of Honggang Oilfield, and the optimizeding mass ratio of the compound polymer is 17:60:23 for ultrahigh molecule, macromolecule and medium molecule polymers.