An Experimental Investigation on the Effects of Polymer-surfactant on the Efficiency of Oil Sweep from Dead-ends

In this study, the effects of polymer-surfactant flooding on oil recovery from dead-ends in a glass micromodel are experimentally investigated. A micromodel containing a long capillary connected to some dead-ends having different aspect ratios is designed and fabricated. Different polymer flooding solutions and combinations of polymer surfactant flooding experiments are carried out at a constant injection rate. The obtained results show that by increasing the concentration of polymer in flooding fluid, the efficiency of sweep from dead-end increases considerably, which could be attributed to the increase of shear stress and the hole-pressure in the dead-ends. The results also show that an increase in the percentage of hydrolyzed and sulfonated groups in polyacrylamide chains leads to higher efficiency of oil sweep from dead-ends. Moreover, the results confirm that the addition of surfactant to polymer flooding solution increases the efficiency of oil sweep from dead-ends considerably, which is much more significant for highly sulfonated polyacrylamide polymers