Experimental Research On The Adaptability Between Hydrophobic Associated Polymer And SZ36-1 Reservoir

After polymer flooding has been applied in onshore oilfields and stabilizing oil production and controlling water production have been achieved, polymer flooding has been explored and piloted in some offshore oilfields and apparent yield-increasing effect has been obtained. In order to further study the action between the system of polymer flooding and the reservoir on offshore oilfields, and to offer the experimental basis for the technical strategy of enhancing oil recovery efficiency through polymer flooding on offshore heavy-oil oilfields, theoretically guided by physical chemistry, macro-molecular material and reservoir engineering, by means of chemical analysis, instrument test and physical simulation, choosing the reservoir and fluid of SZ36-1 oilfield as studying subjects, experiments and theoretical analysis have been carried out on the effect of the system of polymer flooding on the reservoir property and the adsorption and desorption of polymer flooding system in the reservoir and the adaptability between polymer solution and reservoir. Results show that the modifier could restrict the association reaction among the molecular chains of hydrophobic associated polymer, thereby influencing the property of hydrophobic associated polymer solution. The adsorption and desorption of polymer on natural oil sands was affected by many factors such as polymer concentration, β-CD concentration, particle size of oil sands and liquid-solid ratio. The adsorption and desorption of polymer at the surface of cores depend on the factors of injection rate, polymer concentration, β-CD concentration and core permeability. With the change of the association degree among hydrophobic associated polymer molecules, the adaptability between molecule aggregation size and porous size varied. And the adsorption manner of polymer molecules changed as well, which resulted in the variation of the dynamic retention volume of polymer solution when flowing through the pores. As the injection rate increased, polymer molecules’ orientation ability got strengthened, which made them flow into pores with smaller size and dynamic retention volume of polymer increase. Association degree of hydrophobic associated polymer could be modified by modulating polymer concentration or adding β-CD. It can improve the adaptability between polymer solution and heterogeneous reservoirs and enhance the oil-increasing effect of polymer solution.