As a part of a preparation for field application of polymer flooding with HPAM at 20 mPa·c viscosity, series of core flood tests were carried out to determine resistance modification, residual resistance factor and retention factor. Tests were performed with actual core samples taken from reservoir, which is a fine to medium sandstone. In terms of permeability, the reservoir is highly heterogeneous so the samples were divided in 3 groups – high, medium and low permeability. It was expected that values of measured parameters would be more or less dependent on permeability, however, some of the results obtained did not correspond to this trend. When mineral composition of core samples was analyzed it was noticed that some samples have carbonate content up to 70%, while having values of porosity and permeability in the same range as other sandstone samples with low carbonate content. General dependence of experimental results on permeability and carbonate content was established. Further, since carbonates have different wettability characteristic than silicates, a concept of combining Smart Water technology and polymer flooding was tested on samples with high carbonate content. Combined treatment resulted in additional 5% of oil recovery when compared with proper polymer flooding.
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