초록 ▼

Water-soluble polymers comprising an N-vinyl lactam are found to be useful in processes wherein the polymer is introduced into a subterranean wellbore. Polymers useful in the recovery of natural resources are prepared by polymerizing an N-vinyl lactam by free radical initiation, with polymerization

Water-soluble polymers comprising an N-vinyl lactam are found to be useful in processes wherein the polymer is introduced into a subterranean wellbore. Polymers 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.

대표청구항 ▼

A method comprising polymerizing an N-vinyl lactam by free radical initiation employing an aqueous polymerization medium comprising at least one alkali metal salt electrolyte and at least one alkaline earth metal salt electrolyte in a concentration sufficient to give an Ionic Strength of 0.4 to 0.8

A method comprising polymerizing an N-vinyl lactam by free radical initiation employing an aqueous polymerization medium comprising at least one alkali metal salt electrolyte and at least one alkaline earth metal salt electrolyte in a concentration sufficient to give an Ionic Strength of 0.4 to 0.8 and wherein divalent cations constitute 10 to 50 weight percent of total cations, and wherein the resulting polymer has a K value of 150 or greater. A method comprising polymerizing an N-vinyl lactam in a medium consisting of tertiary butanol by free radical initiation.