05208216 is referenced by 62 patents and cites 6 patents.

A low viscosity drilling fluid and method for stabilizing a downhole shale formation are disclosed. The fluid comprises an aqueous solution of a partialy transamidated hydrolyzed acrylamide copolymer, potassium chloride, a weighting agent and an optional viscosifying agent. The copolymer comprises from about 50 to about 98 mole percent primary amide functionality, from about 0.1 to about 15 mole percent secondary amide functionality and from about 2 to about 50 mole percent of the acrylate salt. The drilling fluid has a density out from about 8 to about 18 pounds per gallon and a viscosity of from about 5 to about 30 centistokes.

Title
Acrylamide terpolymer shale stabilizing additive for low viscosity oil and gas drilling operations
Application Number
714666
Publication Number
5208216
Application Date
June 30, 1992
Publication Date
May 4, 1993
Inventor
Robert K Gabel
Sugar Land
TX, US
Dodd W Fong
Naperville
IL, US
C Darwin Williamson
Sugar Land
TX, US
Agent
Andrew S Pryzant
Daniel N Lundeen
Robert A Miller
Assignee
Nalco Chemical Company
IL, US
IPC
C09K 7/02
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