Aqueous drilling fluid and mobility control solution for use on recovery
AssigneeLever Brothers Company
InventorsRoger B. Cox, David C. Steer
Life of this patent
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Abstract
An heteropolysaccharide known as Biopolymer PS 87 comprises glucose, galactose, mannose, glucuronic acid and fucose. Biopolymer PS 87 is pseudoplastic, has a consistency at 20.degree. C. of at least 150 poise and a yield stress value at 20.degree. C. of at least 30 dynes/cm.sup.2. Biopolymer PS 87 is synthesized by a strain of Bacillus polymyxa or a genetically similar micro-organism and has many domestic and industrial uses as a suspending agent or thickener.
Claims7
An aqueous drilling fluid comprising an aqueous medium containing from 0.05 to 3% by weight of Biopolymer PS 87 said Biopolymer PS 87 being a heteropolysaccharide which comprises from 40 to 45% by weight of glucose, from 10 to 20% by weight galactose, from 25 to 30% by weight mannose, from 6 to 13% by weight glucuronic acid and from 0 to 1.5% by weight fucose, a 1% by weight solution of said Biopolymer PS 87 having pseudoplastic properties, a consistency at 20.degree. C. of at least 150 poise and a yield stress value of 20.degree. C. of at least 30 dynes/cm.sup.2.
An aqueous mobility control solution for use in oil recovery comprising an aqueous fluid of from 0.005 to 0.5% by weight of Biopolymer PS 87 said Biopolymer PS 87 being a heteropolysaccharide which comprises from 40 to 45% by weight of glucose, from 10 to 20% by weight galactose, from 25 to 30% by weight mannose, from 6 to 13% by weight glucuronic acid and from 0 to 1.5% by weight fucose, a 1% by weight solution of said Biopolymer PS 87 having pseudoplastic properties, a consistency at 20.degree. C. of at least 150 poise and a yield stress value at 20.degree. C. of at least 30 dynes/cm.sup.2.
Dependencies are inferred from the claim text.