The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 17, 2011
Filed:
Jun. 21, 2007
Simon Neil Duncum, Bracknell, GB;
Christopher Alan Sawdon, Par, GB;
Simon Neil Duncum, Bracknell, GB;
Christopher Alan Sawdon, Par, GB;
BP Exploration Operating Company Limited, Middlesex, GB;
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 —CH.CH.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 Cto Calkyl 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 Cto Calpha-olefin, a Cto Calkyl vinyl ether, an acrylamide of the general formula CH═CRC(O)NHR(I) where Ris selected from H and Cto Calkyl groups and Ris a Cto Calkyl group, and an acrylate of the general formula CH═CRC(O)OR(II) where Ris H or methyl and Ris a Cto Calkyl group; and additionally containing at least one additive selected from additional fluid loss control agents, bridging particulate materials, finely dispersed additives for increasing the fluid density, thinners, and shale inhibitors.