Visco-elastic property studies on polymer flooding systems with high concentrations

摘要

Polymer flooding and ASP flooding has improved oil recovery a lot in Daqing oil field. In ASP flooding, the existence of alkali decreases the visco-elastic characteristic of polymer, which decreases the oil recovery of polymer flooding. The aim of this paper was to study the visco-elastic characteristic, shear resistance in high concentration and high molecular weight polymer flooding, and analyzed the suitable parameter of it. They can provide the theory of polymer flooding development and application research. Polymer flooding is an effective way in enhanced oil recovery. Study confirmed, polymer solution with sticky elastic can effectively improve the oil displacement efficiency, reduce residual oil saturation and the reason was the tensile force parallel flow direction in porous media caused by viscoelastic effect. Through the optimization of polymer filling solution, with sticky elastic polymer flooding of high molecular weight and high concentrations replacing alkali-surfactants-polymer flooding, it can dig oil increase potential of polymer flooding technology, enhance oil recovery, and greatly improve the economic benefit of oil field. So, the study on the stability, viscoelastic and shear properties of the polymer system in high concentration (> 1000 mg/L) can provide experimental base for a high concentration of polymer flooding, it also has important significance on theory of polymer flooding development and application research.