John K Westerman

US Patent:

51862573, Feb 16, 1993

Filed:

Dec 10, 1991

Appl. No.:

7/805283

Inventors:

Allan Stahl - Humble TX
John Westerman - Wadsworth OH
Henry L. Hsieh - Bartlesville OK
James H. Hedges - Bartlesville OK
Geir Bjornson - Bartlesville OK

Assignee:

Phillips Petroleum Company - Bartlesville OK

International Classification:

E21B 4322

US Classification:

166273

Abstract:

Water-soluble polymers comprising N-vinyl amide such as 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. The invention also broadly encompasses utilizing a water-soluble polymer comprising at least one of a hydrophilic vinyl-containing sulfonate, phosphonate or ester and/or hydrophilic N-vinyl lactam for applications under hostile conditions.