Role of polymer in polymer/foam combinational profile controlling and flooding technology

In order to study the influence of polymer on stability and regeneration ability of foam during polymer/foam combinational profile control and flooding technology, aiming at polymer/foam compound system ES-70/012 for offshore oilfield profile control and flooding, gas bubble stabilization of polymer in bulk foam was researched using Waring-Blender method. Furthermore, comparative studies on the sealing of foam and polymer/foam system were conducted by long sand-packed pipe mode respectively. The experimental results show that half-life of foam has increased from 12.5 minutes to 58.0 minutes by adding 1000 mg/L polymer SNF3640 under conditions of 57 degree. Under the same conditions, the sealing of polymer/foam system was better than that of corresponding foam system, and the average blocking capacity were up to 3.2 MPa/m and 1.8 MPa/m respectively. On the other hand, polymer increased the critical injecting rate of foam-forming and decreased the ability of foam regeneration at low injecting rate which were unfavorable for foam profile controlling and flooding in deep reservoir. Therefore, it is necessary to reduce concentration of polymer and enhance the regeneration of foam in polymer/foam combinational deep profile controlling and flooding.