| 摘要 |
This invention relates to a method for enhanced recovery of petroleum from a subterranean oil-bearing formation. More particularly, this invention relates to secondary or tertiary recovery of oil employing a polymer-thickened aqueous drive fluid. The polymeric viscosifier for the drive fluid is selected from a class of hydrophobically associating, water soluble polymers containing one or more water soluble monomers and a water insoluble monomer group. The water soluble groups are acrylamide and a salt of acrylic acid and the water insoluble group is a higher alkylacrylamide. These polymers, when dissolved in an aqueous brine solution, have the ability to substantially increase the viscosity of the aqueous solution. The control of displacement fluid mobility results in more uniform sweep efficiency and improved oil recovery. In addition, aqueous solutions of these hydrophobically associating polymers exhibit enhanced viscosification, reduced salt sensitivity and other desirable rheological properties found useful in chemically enhanced oil recovery processes. |
