Experimental Study on Improving Oil Displacement Efficiency by Air Foam Flooding in Tight Oil Layer

Abstract

The tight oil layer is poor in physical property, small pore throat radius, serious heterogeneity of reservoir, low flooding efficiency, poor water flooding efficiency and final recovery is lower than 10%. In order to further improve the oil displacement yield and simulate the conditions of oil layer, we have carried out the experiment of air foam liquid system to flooding oil, and studied the rule of improving the displacement efficiency of air tight foam reservoir. The experimental results show that the density of Gaotaizi water flooding ultimate oil displacement efficiency is 48.95% on average, after water flooding to air - foam flooding alternating final displacement efficiency is high up 79.63%, the oil displacement efficiency can be increased by 26.92%; a short alternately displacement than the big slug is better, the gas-liquid ratio is too high, the breakthrough time of change in short, flooding effect, direct air - foam liquid slug can achieve good flooding effect. That air foam flooding can improve the oil displacement efficiency of dense oil after water flooding by air - foam liquid slug, gas-liquid ratio, cycle injection parameter optimization, to further improve the dense oil displacement effect, the results of air foam flooding field test has the reference and guiding significance for the tight reservoir.