关键词: 低渗透油藏, 空气泡沫驱,  , 增油机理, 驱油效率

Abstract: The airfoam flooding technology has been applied well in middlehigh permeability reservoirs, however, it is less applied in low permeability reservoirs. The airfoam flooding mechanism and injection mode of low permeability reservoirs were studied throw literature research and the feasibility of airfoam flooding in low permeability reservoir was proceeded by indoor simulation experiment and field test. The results showed that when the residual oil saturation was lower than 20% in the high permeability layer, the foam fluid system can play a very good role and block the high permeability layer. A large number of crude oil in the low permeability layers was displaced during the airfoam flooding stage and the oil displacement efficiency rised from 8.33% to 50.55%. The water content of the field test well group decreased from 98% to 54%, the daily fluid production rate dropped from 3.5 m3 to 1 m3, and the daily oil production increased from 0.07 m3 to 0.46 m3. The airfoam flooding technology has tremendous potential in the development of low permeability reservoirs and has a certain reference function of stabilizing oil output and controlling water content for the similar reservoirs.

Key words: Low permeability reservoir,     ,  Airfoam flooding,     ,  Mechanism of EOR,   ,  Oil displacement efficiency