US5032297A
Expired / Lapsed
US
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Enzymatically degradable fluid loss additive
Assignee: Ecolab USA Inc
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Filing: 1989-05-19
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Granted: 1991-07-16
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Expires: 2009-05-19
Abstract
Abstract In treating oil well down hole bores, a method of treating subterranean formations by fracturing by utilization of a fluid loss additive (FLA) comprising starch or a mixture of natural and modified starches plus an enzyme which degrades the alpha linkage of starch and does not the degrade the beta linkage of guar and modified guar where used as a viscosity modifier. Natural/modified starches are utilized in a preferred ratio of 3:7 to 7:3 or 1:9 to 9:1 with optimum at 1:1, and the mix is used in the dry form for application from the surface down the bore hole.
Inventors
- 👤 Charles D. Williamson
- 👤 Stephan J. Allenson
- 👤 Robert K. Gabel
- 👤 David A. Huddleston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:54
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74; C09K8/76; Y; Y10; Y10S; Y10S507/00; Y10S507/921; Y10S507/922
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
60 words
In oil well down hole bore treatment, a method of treating subterranean formations which entails the addition of an effective concentration, for the purpose of hydraulic fracturing, of guar or modified guar as a viscosity modifier, starch and an enzyme which degrades the alpha linkage of the starch but does not affect the beta linkage of guar, and modified guar.
Claim 2
Dependent Claim
60 words
In oil well down hole bore treatment, a method of treating subterranean formations which entails the addition of an effective concentration, for the purpose of hydraulic fracturing, of guar or modified guar as a viscosity modifier, starch and an enzyme which degrades the alpha linkage of the starch but does not affect the beta linkage of guar, and modified guar.
Claim 3
Dependent Claim
42 words
In oil well down hole bore treatment, a method of treating subterranean formations by the addition of an effective concentration, for the purpose of hydraulic fracturing, of natural and modified starches and an enzyme which degrades the alpha linkages in the starches.
Claim 4
Dependent Claim
42 words
In oil well down hole bore treatment, a method of treating subterranean formations by the addition of an effective concentration, for the purpose of hydraulic fracturing, of natural and modified starches and an enzyme which degrades the alpha linkages in the starches.
Claim 5
Dependent Claim
41 words
According to claim 2, a method of treating subterranean formations by the addition of an effective concentration, for the purpose of hydraulic fracturing, of a mixture of natural starches and an enzyme capable of degrading the alpha linkage of the starch.
Claim 6
Dependent Claim
41 words
According to claim 2, a method of treating subterranean formations by the addition of an effective concentration, for the purpose of hydraulic fracturing, of a mixture of modified starches and an enzyme capable of degrading the alpha linkage of the starches.
Claim 7
Dependent Claim
28 words
An enzymatically degradable fluid loss additive consisting of a mixture of natural and modified starches in a ratio of about 9:1 to 1:9, and an alpha linkage enzyme.
Claim 8
Dependent Claim
28 words
An enzymatically degradable fluid loss additive consisting of a mixture of natural and modified starches in a ratio of about 9:1 to 1:9, and an alpha linkage enzyme.
Claim 9
Dependent Claim
33 words
According to claim 5, an enzymatically degradable fluid loss additive consisting of natural starch and a mixture of modified starches in a ratio of about 7:3 to 3:7, and an alpha linkage enzyme.
Claim 10
Dependent Claim
44 words
An enzymatically degradable fluid loss additive consisting of guar or modified guar as a viscosity modifier, a mixture of modified starches and an enzyme which degrades the alpha linkage of starch but does not affect the beta linkage of any guar or modified guar.
Claim 11
Dependent Claim
44 words
An enzymatically degradable fluid loss additive consisting of guar or modified guar as a viscosity modifier, a mixture of modified starches and an enzyme which degrades the alpha linkage of starch but does not affect the beta linkage of any guar or modified guar.
Claim 12
Dependent Claim
64 words
According to claim 7, an enzymatically degradable fluid loss additive consisting of guar or modified guar as a viscosity modifier, a mixture of modified starch and an enzyme selected from one member of a group consisting of alpha amylase, beta amylase and gluco amylase, which degrades the alpha linkage of starch but does not affect the beta linkage of any guar or modified guar.
Claim 13
Dependent Claim
30 words
According to claim 8, a fluid loss additive consisting of guar or modified guar as a viscosity modifier, a mixture of modified starch and an enzyme consisting of alpha amylase.
Claim 14
Dependent Claim
30 words
According to claim 8, a fluid loss additive consisting of guar or modified guar as a viscosity modifier, a mixture of modified starch and an enzyme consisting of beta amylase.
Claim 15
Dependent Claim
30 words
According to claim 8, a fluid loss additive consisting of guar or modified guar as a viscosity modifier, a mixture of modified starch and an enzyme consisting of gluco amylase.
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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) | 1994-07-15 | 1995-01-14 | 1995-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-15 | 1999-01-14 | 1999-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-15 | 2003-01-14 | 2003-07-16 | $7700.00 | Window Closed / Lapsed |