Inventors:
Stefano C. Crema - Ypsilanti MI
Clare H. Kucera - Tulsa OK
Gerd Konrad - Limburgerhof, DE
Heinrich Hartmann - Limburgerhof, DE
International Classification:
C09K 700
C08B 11193
C08B 1100
C08B 1112
Abstract:
A cementing composition useful in cementing oil, gas and water wells, comprising water, hydraulic cement and an effective amount of water soluble fluid loss additive comprised of a blend of a copolymer of acrylamide/vinyl imidazole in a weight percent ratio of from about 95:5 to 5:95, said copolymer having a molecular weight range of from about 100,000 to 3,000,000, and a terpolymer of acrylamide/acrylamidomethylpropane sulfonic acid sodium salt/vinyl imidazole in a weight percent ratio of 60:20:20, said terpolymer having a molecular weight range of from about 100,000 to 3,000,000. The blend is comprised of a weight percent ratio of copolymer to terpolymer in the range of 20:80 to 80:20. The composition can also optionally include a dispersant such as sodium or potassium salts or a sulfonated naphthalene formaldehyde condensate.