Patent US4758356A successfully refreshed from Google Patents.
US4758356A
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Process for preparing Xanthomonas heteropolysaccharides
Assignee: Shell USA Inc
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Filing: 1987-03-20
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Granted: 1988-07-19
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Expires: 2007-03-20
Abstract
Abstract Process for preparing Xanthomonas heteropolysaccharide from Xanthomonas campestris NCIB 11854 and use of the latter, e.g. as viscosity modifier in an aqueous solution, and in a drilling fluid and use in connection with well treatments, and enhanced oil recovery.
Inventors
- 👤 John D. Downs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:50
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/84; C09K8/86; C09K8/88; C09K8/90; C09K8/905; C09K8/02; C09K8/04; C09K8/06; C09K8/08; C12; C12N; C12N1/00; C12N1/20; C12N1/205; C12P; C12P19/00; C12P19/04; C12P19/06; C12R; C12R2001/00; C12R2001/01; C12R2001/64; Y; Y10; Y10S; Y10S435/00; Y10S435/813; Y10S435/8215; Y10S435/822; Y10S435/91; Y10S507/00; Y10S507/935; Y10S507/936
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
55 words
A method of modifying the viscosity of an aqueous solution which comprises adding a viscosity modifying amount of a heteropolysaccharide to said aqueous solution, said heteropolysaccharide being prepared by growing Xanthomonas campestris NCIB 11854 in a chemically defined aqueous nutrient medium by aerobic fermentation of an assimilable carbohydrate and nitrogen source and recovering the heteropolysaccharide.
Claim 2
Independent Claim
55 words
A method of modifying the viscosity of an aqueous solution which comprises adding a viscosity modifying amount of a heteropolysaccharide to said aqueous solution, said heteropolysaccharide being prepared by growing Xanthomonas campestris NCIB 11854 in a chemically defined aqueous nutrient medium by aerobic fermentation of an assimilable carbohydrate and nitrogen source and recovering the heteropolysaccharide.
Claim 3
Dependent Claim
40 words
A drilling fluid comprising water and 0.06-1.5% by weight of a heteropolysaccharide prepared by growing Xanthomonas campestris NCIB 11854 in a chemically defined aqueous nutrient medium by aerobic fermentation of an assimilable carbohydrate and nitrogen source and recovering the heteropolysaccharide.
Claim 4
Dependent Claim
40 words
A drilling fluid comprising water and 0.06-1.5% by weight of a heteropolysaccharide prepared by growing Xanthomonas campestris NCIB 11854 in a chemically defined aqueous nutrient medium by aerobic fermentation of an assimilable carbohydrate and nitrogen source and recovering the heteropolysaccharide.
Claim 5
Independent Claim
59 words
A method for displacing a fluid through a well and/or a permeable subsurface formation communicating with the well by injecting into the well an aqueous solution comprising water and a heteropolysaccharide prepared by growing Xanthomonas campestris NCIB 11854 in a chemically defined aqueous nutrient medium by aerobic fermentation of an assimilable carbohydrate and nitrogen source and recovering the heteropolysaccharide.
Claim 6
Independent Claim
59 words
A method for displacing a fluid through a well and/or a permeable subsurface formation communicating with the well by injecting into the well an aqueous solution comprising water and a heteropolysaccharide prepared by growing Xanthomonas campestris NCIB 11854 in a chemically defined aqueous nutrient medium by aerobic fermentation of an assimilable carbohydrate and nitrogen source and recovering the heteropolysaccharide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-19 | 1992-01-18 | 1992-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-19 | 1996-01-18 | 1996-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-19 | 2000-01-18 | 2000-07-19 | $7700.00 | Window Closed / Lapsed |