Patent US4981520A successfully refreshed from Google Patents.
US4981520A
Expired / Lapsed
US
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Oil reservoir permeability profile control with crosslinked welan gum biopolymers
Assignee: Mobil Oil AS
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Filing: 1988-12-12
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Granted: 1991-01-01
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Expires: 2008-12-12
Abstract
Abstract A composition capable of selectively plugging highly permeable zones in a subterranean formation. The composition forms a gel subsequent to its injection into the formation via an injection well. The composition comprises an aqueous solution of a welan gum heteropolysaccharide biopolymer produced by the fermentation of a microorganism of the genus Alcaligenes, a phenolic compound, an aldehyde and water. The compositions of this invention will form stable gels even in low salinity brines. Also provided is a process for selectively plugging regions of higher permeability within an oil-bearing subterranean formation to improve sweep efficiency during a fluid flood oil recovery process using the gel-forming compositions of this invention.
Inventors
- 👤 Dennis H. Hoskin
- 👤 Thomas O. Mitchell
- 👤 Paul Shu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:48
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; C09K8/50; C09K8/504; C09K8/506; C09K8/508; C09K8/514
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
114 words
An aqueous crosslinked biopolymer gel comprising: (a) water; (b) a viscosifying amount of a welan gum heteropolysaccharide biopolymer produced by fermentation with a microorganism of the genus Alcaligenes; (c) about 0.01 to about 2.0 weight percent of at least one phenolic compound selected from the group consisting of phenol, resorcinol, catechol, phloroglucinol, pyrogallol, 4,4'-diphenol and 1,3-dihydroxynaphthalene; and (d) about 0.01 to about 3.0 weight percent of at least one aldehyde component selected from the group consisting of aliphatic monoaldehydes, aromatic monoaldehydes, aliphatic dialdehydes and aromatic dialdehydes, which amounts of said phenolic compound and said aldehyde component are sufficient to cause gelation of the aqueous solution of said biopolymer and produce the crosslinked polymer gel.
Claim 2
Dependent Claim
114 words
An aqueous crosslinked biopolymer gel comprising: (a) water; (b) a viscosifying amount of a welan gum heteropolysaccharide biopolymer produced by fermentation with a microorganism of the genus Alcaligenes; (c) about 0.01 to about 2.0 weight percent of at least one phenolic compound selected from the group consisting of phenol, resorcinol, catechol, phloroglucinol, pyrogallol, 4,4'-diphenol and 1,3-dihydroxynaphthalene; and (d) about 0.01 to about 3.0 weight percent of at least one aldehyde component selected from the group consisting of aliphatic monoaldehydes, aromatic monoaldehydes, aliphatic dialdehydes and aromatic dialdehydes, which amounts of said phenolic compound and said aldehyde component are sufficient to cause gelation of the aqueous solution of said biopolymer and produce the crosslinked polymer gel.
Claim 3
Dependent Claim
13 words
The composition of claim 1, wherein said welan gum biopolymer is heteropolysaccharide S-130.
Claim 4
Dependent Claim
17 words
The composition of claim 1, wherein said aldehyde compound is formaldehyde and said phenolic compound is resorcinol.
Claim 5
Dependent Claim
27 words
The composition of claims 1, 2 or 3, wherein said welan gum biopolymer is present in an amount ranging from about 0.1 to about 5.0 weight percent.
Claim 6
Dependent Claim
15 words
The composition of claims 1, 2, or 3, wherein said water is a low-salinity brine.
Claim 7
Dependent Claim
12 words
The composition of claim 4, wherein said water is a low-salinity brine.
Claim 8
Dependent Claim
23 words
The composition of claims 1, 2, or 3, wherein said phenolic compound and said aldehyde compound are condensed to form a phenolic resin.
Claim 9
Dependent Claim
20 words
The composition of claim 4, wherein said phenolic compound and said aldehyde compound are condensed to form a phenolic resin.
Claim 10
Dependent Claim
20 words
The composition of claim 5, wherein said phenolic compound and said aldehyde compound are condensed to form a phenolic resin.
Claim 11
Dependent Claim
20 words
The composition of claim 6, wherein said phenolic compound and said aldehyde compound are condensed to form a phenolic resin.
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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) | 1993-12-31 | 1994-07-02 | 1995-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-31 | 1998-07-02 | 1999-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-31 | 2002-07-02 | 2003-01-01 | $7700.00 | Window Closed / Lapsed |