Water-soluble polymers comprising an N-vinyl lactam are found to be useful in processes wherein the polymer is introduced into a subterranean wellbore.PPPolymers useful in the recovery of natural resources are prepared by polymerizing an N-vinyl lactam by free radical initiation, with polymerization conducted in an aqueous solution polymerization medium preferably containing a mixture of dissolved electrolytes, or in a polymerization medium consisting essentially of a tertiary alkanol. Copolymers of such N-vinyl lactams with unsaturated amides, and terpolymers prepared by polymerizing an N- vinyl lactam and an unsaturated amide with a selected termonomer compound are also useful when prepared by these methods.
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