Well cementing aids

US6277900A · kind A · utility

Assignee

• Clariant Corporation · DE

Inventors

• Reinhard J. Oswald · Wien, AT
• Volker Frenz · Hochheim, DE
• Juergen Tonhauser · Oestrich-Winkel, DE
• Aranka Tardi · Neuberg, DE
• Pierre Maroy · Saint-Galmier, FR
• Florence L'Alloret · Paris, FR

Key dates

• Filing date: Nov 19, 1998
• Grant date: Aug 21, 2001
• Expiry date: Nov 19, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F220/585
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention relates to copolymers consisting of PA1 (a) 1-99% by weight of structural units of the formula (1) ##STR1## PA1 where R.sup.1 is hydrogen or methyl, R.sup.4 is C.sub.1 -C.sub.22 -alkylene, R.sup.5 is C.sub.1 -C.sub.22 -alkyl or hydrogen, and X is ammonium, lithium, sodium, potassium, an amine or a mixture of these substances, and PA1 (b) 99-1% by weight of structural units of the formula (2) ##STR2## PA1 where R.sup.1 is hydrogen or methyl, R.sup.2 and R.sup.3, independently of one another, are hydrogen, or C.sub.2 -C.sub.22 -alkyl, wherein component b) is not hydrolysed and the copolymers have been prepared by a solution precipitation polymerization in a nonaqueous solvent or a water-miscible, organic solvent having a low water content which is a precipitant for the copolymer. The invention furthermore relates to a process for cementing subterranean wells using a cement slurry comprising the following components: PA0 a) water of various salinity PA0 cement PA0 a novel copolymer in a concentration of 0.01-5% bwoc, preferably from 0.05 to 0.9% bwoc.