Composition and method for recovery of petroleum and gas

Abstract

The present invention provides a composition for recovery of petroleum and gas, which comprises (a) a copolymer having a molecular weight of 100,000 or more, composed of 30-75 mole % of N-vinylpyrrolidone unit, 5-70 mole % of (meth)acrylamide unit and 0-20 mole % of (meth)acrylic acid unit or a salt thereof, (b) a water-soluble aldehyde, (c) a phenol compound, and (d) water. This composition can form a gel in a required gelling time even at high temperatures and even in the presence of bivalent metal ions and accordingly can be used for efficient recovery of petroleum and gas.

Dependencies are inferred from the claim text.