ENHANCED OIL RECOVERY WITH HYDROPHOBICALLY ASSOCIATING POLYMERS

摘要

ABSTRACT OF THE DISCLOSUREThis invention relates to a method forenhanced recovery of petroleum from a subterraneanoil-bearing formation. More particularly, thisinvention relates to secondary or tertiary recoveryof oil employing a polymer-thickened aqueous drivefluid. The polymeric viscosifier for the drivefluid is selected from a class of hydrophobicallyassociating, water soluble polymers containing oneor more water soluble monomers and a water insolublemonomer group. The water soluble groups areacrylamide and a salt of acrylic acid and the waterinsoluble group is a higher alkylacrylamide. Thesepolymers, when dissolved in an aqueous brine solu-tion, have the ability to substantially increase theviscosity of the aqueous solution. The control ofdisplacement fluid mobility results in more uniformsweep efficiency and improved oil recovery. Inaddition, aqueous solutions of these hydrophobicallyassociating polymers exhibit enhancedviscosification, reduced salt sensitivity and otherdesirable rheological properties found useful inchemically enhanced oil recovery processes.