Abstract: In the field testing process of alkali-polymer combination flooding，the alkali compounding with produced water or formation water appears unmatched，which brings about the crustation of ground pipeline and performance descent of the displacement system.Under the reservoir condition of upper Ng groupⅡ，Yangsanmu Block 3，Dagang Oilfield，alkali-polymer combination flooding dissolved with produced water is investigated.The matching of active alkali with produced water is better than the sodium carbonate.The interface tension is two order lower than that of sodium carbonate solution/crude oil and IFT reaches 10^-3 mN/m，the ability of resistance calcium and magnesium ions is about 500mg/L.The emulsification of active alkali and the crude oil is strong.Four kinds of polymer and the alkali have tested for the compatibility in alkali-polymer combination flooding system.The polymer HTPW-111 is better matched with alkali and salt-resisting.Active alkali-polymer combination flooding system with produced water still keeps the property of increasing viscosity action and reducing oil/water interfacial tension of polymer flooding.

Key words: improvement alkali-polymer combination flooding, produced water, ultra-low interfacial tension, increasing viscosity of alkali-polymer