Abstract: The foam effect on improving the core sweep efficiency and reducing permeability are investigated
by foam flooding in porous media experiments. The influence of α-olefin sulfonate （AOS ） ， hydrolyzed polyacry-
lamide （HPAM）concentration， gasliquidratio， corepermeability， andinjectionmethodsonfoamfloodingproperty
are explored. The experiment results show that foam flooding resistance coefficient and residual resistance coeffi-
cient increase with the increasing concentration of AOS and HPAM. The foam flooding resistance coefficient and
residual resistance coefficient in the non-oil rock heart are more than three times of those in the oil-bearing rock.
Under the condition that AOS and HPAM concentration are greater than a certain value， foam flooding resistance
coefficient and residual resistance coefficient are stabilized. Appropriate increasing ratio of gas-liquid can improve
foamfloodingcontrolability， buttoomuchratioofgas-liquidwillcausegaschanneling. Thesamefoamsystemdoes
not improve flooding control ability of all different permeability cores. Advanced foam injection leads to the best
mobility control than other ways. The mobility control of the alternating injection of liquid and gas foam decrease
with the increase of alternating slug.

Key words: foam flooding, resistance coefficient, gas liquid ratio, injection method