The Oil Displacement Mechanism of Viscoelastic of High-Concentration Polymer in Lamadian Oilfield

The field test of high-concentration displacement is implemented in Lamadian Oilfield North West Block. The value of enhanced oil recovery in the central area is up to 20 percent or more. In order to explore the reason of good stimulation effect of high concentration polymer flooding in Lamadian Oilfield, the mechanism of high concentration polymer systems for EOR is conducted in this paper. The high concentration is characterized by the viscosity and elasticity of polymer in this article. The results showed that: the concentration of polymer with 25 million molecular weight reach to 3000mg/L, the increases value of viscoelasticity is the largest. So high-concentration polymer is defined as 3000mg/L. Compared with conventional polymer flooding, high concentration polymer has a greater ability to expand swept volume and effectiveness of wash oil.