Mobility control and enhanced oil recovery using partially hydrolysed polyacrylamide (PHPA)

Polymers are often used as mobility controller for enhanced oil recovery. The present paper deals with the application of partially hydrolysed polyacrylamide (PHPA) polymer in enhanced oil recovery after the conventional water flooding. Experimental results show that viscosity of PHPA solution increases significantly on addition of small quantity of polymer, which in turn decreases the mobility ratio. The effect of frontal-advance velocity on the total relative mobility at different concentration of polymer has been discussed. A series of flooding experiments were performed in a flooding apparatus to observe the efficiency of polymer flooding at different concentration of PHPA. The crude oil is collected from Ahmedabad oil-field, India (total acid number of 0.038 mg KOH/g, gravity of 38.86 degrees API and viscosity of 119 mPa.s at 30 degrees C). The additional oil recoveries vary 16% to 20% of original oil in place (OOIP) depending on the polymer concentration.