Experimental Study On Application Of Betaine System In The Class ? Reservoir In Daqing

Because of the high clay content in the class ? reservoir,leading to the serious loss of surfactant adsorption.Using Daqing natural sand packed tubular model,the length is 20 cm,50 cm and 100 cm,and the permeability was(343~482)×10-3?m2,the injection rate is 1m/d and the experiment temperature is 45?,the adsorption and migration of betaine surfactant were studied and the effect of oil displacement was evaluated.In order to compare with conventional flooding agent,the adsorption experiment and oil displacement experiment of ternary system of Interfacial Tension were carried out under the same conditions.The experimental results show that: system,under the condition of sand packed tubular model without oil,the adsorption makes the front of surfactant to migrate in the way of non-piston-like movement.When the injection volume of the betaine binary system reaches to 16.0~34.0 PV,the interfacial tension of produced liquid reaches to the ultra-low value,the quantity of dynamic saturated adsorption of betaine binary system is 6.67~22.41 mg/g,and the adsorption capacity in the oil-free model is higher than that in the oil-bearing model;after the injection PV of the betaine binary system reaches to the1.6,the produced liquid flows stably in the outlet and contains polymer with a certain viscosity.Compared with the mahogany sulfonate ternary system,betaine surfactants have more severe adsorption losses in the class ? reservoir.Due to the adsorption of betaine system and the mahogany sulfonate ternary system in sand filling pipe,the oil displacement efficiency is reduced,the adsorption of betaine in the sand filled pipe is stronger,which is not conducive to the improvement of oil recovery,but the betaine system has good injection.In order to optimize the auxiliary agent for the betaine system in Daqing,which is suitable in the class ? reservoir,with the Beijing No.1 betaine surfactant?Daqing four plant simulated oil and Daqing experimental zone in four plant reinjection sewage,The aqueous solution of indoor emulsion and medium volume as an indicator,on the basis of screening emulsifier and polymer,using the effective permeability of(94 ~ 199)× 10-3?m2 of the Bei Lei core,the emulsifier formulation of betaine was optimized,and the binary system emulsifier-agglomerate was optimized.The two component emulsifier agglomerate slug optimization and the binary system emulsifier were optimized.Experimental results show:polymer(2000mg / L +)+ Jing1 + ?(8)compound 0.3% + Co-polymer?1000 mg / L(viscosity 84 mPa.s)the chemical flooding recovery efficiency is highest,reaching to 22.17%,and the resistance coefficient is centered(3.455),it can be used as a preferred formula.