The Experimental Studies Of Influencing Weak Gel Deep Profile Control Factors In The Low Permeability Oil Reservoirs

Due to years of water flooding development in the low permeability oil reservoirs, thereservoir heterogeneity is seirous. It is very widespread that the cyclic water injection isinvalid and that the water production rate of oil well is high. In recent years, as the deepproifle control and oil displacement agent, the weak gel system is widely used in theheterogeneous oil reservoir to improve injection proifle and enhance oil recovery(EOR). Thegood results have been obtained in the high permeability reservoir. However, the geologicalcharacteirstics and the reservoir physical property of low permeability reservoirs differ fromthose of the middle or high permeability reservoir. Its characteirstics include the higherformation-water salinity, the worse reservoir heterogeneity, the smaller pore radius, muchmore rough pore surface and the higher irreducible water saturation. Therefore, weak gelduirng the deep migration is influenced seirously by sheairng, adsorption and dilution.Through indoor static and dynamic simulation experiment, the factors of influencing weak geldeep profile control in the low permeability reservoirs are systematically researched in thethesis. The static evaluation expeirment shows that the different crosslinking weak gel systemshave different adaptability to reservoir environment. By circulation capillary lfow system, thedynamic shear process of two kinds of weak gel systems is researched and analyzed. Theresults show that the weak gel viscosity is reduced with the increase of shear rate and that thedifferent crosslinking weak gel systems have different viscosity recovery performance atfersheairng. Using sand-filled capillary model, the injected ability of weak gel in porous media isresearched. The results show that, the smaller the pore radius is, the more signiifcant the shearthinned behavior of weak gel is; Using natural core, the adsorption of HPAM on the poresurface in the porous media is researched, which shows the Disproportionate PermeabilityReduction(DPR). In a word, in order to get a better effect, it still need to take further measuresto optimize the process of weak gel deep profile control in low permeability reservoir.