Wellbore fluid comprising at least one polymer containing pendant alkyl groups

US7943554B2 · kind B2 · utility

Assignee

• BP EXPLORATION OPERATING COMPANY LIMITED · GB

Inventors

• Simon Neil Duncum · Bracknell, GB
• Christopher Alan Sawdon · Par, GB

Key dates

• Filing date: Jun 21, 2007
• Grant date: May 17, 2011
• Expiry date: Jan 12, 2028

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K2208/18
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Wellbore fluid having a continuous aqueous phase, and containing at least one polymer which (a) has a number average molecular weight in the range of from 10,000 to less than 100,000; (b) contains hydrophilic units such that the polymer is at least 2% soluble in water at a temperature of 20° C. wherein none of said hydrophilic units comprise —CH2.CH2.O— units; and (c) contains pendant alkyl groups having at least 10 carbon atoms. The combined molecular weight of the pendant alkyl groups is in the range of from 15 to 70% by weight based on the weight of the polymer. The polymer is selected from (A) a homopolymer of a compound of general formula HO(O)CCH═CHC(O)OR where R is a C10 to C40 alkyl group; and (B) a copolymer of (i) at least one hydrophilic monomer selected from acrylic acid, methacrylic acid, hydroxyethylmethacrylate, hydroxypropylmethacrylate, maleic acid, maleic anhydride, fumaric acid, itaconic acid, vinyl acetate, acrylamide, N,N-dimethylacrylamide, and N-vinyl pyrrolidone, and (ii) at least one hydrophobic monomer that provides a pendant alkyl group selected from a C12 to C40 alpha-olefin, a C10 to C24 alkyl vinyl ether, an acrylamide of the general formula CH2═CR5C(O…