Aqueous drilling fluid additive
AssigneeMilchem Incorporated
InventorsJames M. Lucas, Alphonse C. Perricone, Dorothy P. Enright
Life of this patent
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Abstract
The invention relates to an aqueous solution of a filtration control agent for utilization in said aqueous drilling fluid, useful in a method of forming a filter cake on the wall of a well for the reduction of filtrate from said drilling fluid, which is effective at high temperatures and pressures, the terpolymer consisting essentially of: (1) an alkali metal acrylate units; (2) hydroxyalkyl acrylate units; and (3) acrylamide.
Claims8
An aqueous solution of a terpolymer filtration control agent for aqueous based drilling fluids having clayey material therein, said terpolymer consisting essentially of (1) from about 5 to about 62 mole percent of alkali metal acrylate units, (2) from about 2 to about 40 mole percent of hydroxyalkyl acrylate units selected from 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and 2-hydroxybutyl acrylate units, and (3) from about 31 to about 91 mole percent of acrylamide units;
- a 0.2% by weight aqueous solution of said terpolymer having a viscosity at about 25.degree. C. of from about 6 centipoises to about 85 centipoises, as determined at a shear rate of 511 reciprocal seconds.
Dependencies are inferred from the claim text.