Patent US4574887A successfully refreshed from Google Patents.
US4574887A
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Method for preparation of viscous aqueous liquids for wellbore injection
Assignee: Mobil Oil AS
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Filing: 1984-09-19
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Granted: 1986-03-11
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Expires: 2004-09-19
Abstract
Abstract A method of preparing viscous aqueous liquids containing Xanthomonas polysaccharides for injection into wellbores. The Xanthomonas polysaccharide is dispersed into relatively fresh water. This dispersion of polysaccharide is then mixed with a relatively saline aqueous makeup solution to provide the final thickened aqueous liquid. Trivalent metal ions may be incorporated in the polysaccharide dispersion prior to the addition of the aqueous saline solution in order to complex the polysaccharide. The complexed polysaccharide solutions are useful for selectively blocking high permeability regions in stratified reservoir formations by injecting the complexes into the formation at shear rates which cause a reversible disruption of the complex; the disrupted complexes penetrate the high permeability regions and when the shearing forces decrease at a certain distance from the wellbore, the complexes re-form to block the high permeability regions selectively.
Inventors
- 👤 Milton K. Abdo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:21
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/84; C09K8/86; C09K8/88; C09K8/90; C09K8/905; Y; Y10; Y10S; Y10S507/00; Y10S507/904; Y10S507/935; Y10S507/936
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
32 words
A method for imparting superior viscosity to an aqueous polysaccharide B1459 solution wherein the aqueous component is hard water consisting of prehydrating the polysaccharide in fresh water before mixing with hard water.
Claim 2
Independent Claim
32 words
A method for imparting superior viscosity to an aqueous polysaccharide B1459 solution wherein the aqueous component is hard water consisting of prehydrating the polysaccharide in fresh water before mixing with hard water.
Claim 3
Dependent Claim
20 words
A method as in claim 1 wherein the fresh water contains inorganic ions up to about 300 parts per million.
Claim 4
Independent Claim
29 words
A method for imparting superior viscosity to an aqueous polysaccharide B-1459 solution consisting of prehydrating the polysaccharide in fresh water and mixing the prehydrated polysaccharide solution with hard water.
Claim 5
Independent Claim
29 words
A method for imparting superior viscosity to an aqueous polysaccharide B-1459 solution consisting of prehydrating the polysaccharide in fresh water and mixing the prehydrated polysaccharide solution with hard water.
Claim 6
Dependent Claim
20 words
A method as in claim 3 wherein the final solution of polysaccharide has an aqueous component which is hard water.
Claim 7
Dependent Claim
21 words
A method as in claim 4 wherein the hard water has an inorganic ion content of 6 weight percent or more.
Claim 8
Independent Claim
32 words
A method of imparting superior viscosity to an aqueous polysaccharide B-1459 solution wherein the aqueous component is hard water consisting of prehydrating the polysaccharide in distilled water before mixing with hard water.
Claim 9
Independent Claim
32 words
A method of imparting superior viscosity to an aqueous polysaccharide B-1459 solution wherein the aqueous component is hard water consisting of prehydrating the polysaccharide in distilled water before mixing with hard water.
Claim 10
Independent Claim
29 words
A method for imparting superior viscosity to an aqueous polysaccharide B-1459 solution consisting of prehydrating the polysaccharide in distilled water and mixing the prehydrated polysaccharide solution with hard water.
Claim 11
Independent Claim
29 words
A method for imparting superior viscosity to an aqueous polysaccharide B-1459 solution consisting of prehydrating the polysaccharide in distilled water and mixing the prehydrated polysaccharide solution with hard water.
Claim 12
Dependent Claim
130 words
In a method of preparing a viscous aqueous liquid for introduction into a well penetrating the earth, the method comprising: (a) incorporating a water-dispersible polysaccharide produced by addition of bacteria of the genus Xanthomonas on a carbohydrate into an aqueous liquid having a salinity within the range of 0-0.03 weight percent, (b) incorporating trivalent metal ions selected from the group consisting of aluminum, chromium, and iron ions into said aqueous liquid in a concentration sufficient to effect complexing of said polysaccharide, (c) subsequent to steps (a) and (b), adding an aqueous saline makeup solution to said aqueous liquid containing said polysaccharide and said trivalent metal ions to increase the salinity thereof to a value of at least 0.5 weight percent, and (d) thereafter introducing said aqueous liquid into said well.
Claim 13
Dependent Claim
130 words
In a method of preparing a viscous aqueous liquid for introduction into a well penetrating the earth, the method comprising: (a) incorporating a water-dispersible polysaccharide produced by addition of bacteria of the genus Xanthomonas on a carbohydrate into an aqueous liquid having a salinity within the range of 0-0.03 weight percent, (b) incorporating trivalent metal ions selected from the group consisting of aluminum, chromium, and iron ions into said aqueous liquid in a concentration sufficient to effect complexing of said polysaccharide, (c) subsequent to steps (a) and (b), adding an aqueous saline makeup solution to said aqueous liquid containing said polysaccharide and said trivalent metal ions to increase the salinity thereof to a value of at least 0.5 weight percent, and (d) thereafter introducing said aqueous liquid into said well.
Claim 14
Dependent Claim
28 words
The method of claim 8 further comprising the step of, subsequent to steps (a) and (b) and prior to step (c), incorporating a biocide into said aqueous liquid.
Claim 15
Dependent Claim
41 words
The method of claim 8 further comprising the step of, subsequent to steps (a) and (b) and prior to step (c), adding an aqueous solution of an alkaline agent into said aqueous liquid containing said polysaccharide and said trivalent metal ions.
Claim 16
Dependent Claim
30 words
The method of claim 8 wherein said trivalent metal ions are incorporated into said aqueous liquid by mixing an aqueous solution of said trivalent metal ions with said aqueous liquid.
Claim 17
Dependent Claim
13 words
The method of claim 8 wherein said trivalent metal ions comprise chromium ions.
Claim 18
Dependent Claim
31 words
The method of claim 8 wherein the concentration of said trivalent metal ions in said aqueous liquid at the conclusion of step (c) is no greater than 25 parts per million.
Claim 19
Dependent Claim
19 words
The method of claim 8 wherein said polysaccharide is a polysaccharide produced by action of the bacterium Xanthomonas campestris.
Claim 20
Dependent Claim
13 words
The method of claim 14 wherein said trivalent metal ions comprise chromium ions.
Claim 21
Dependent Claim
125 words
In a method of preparing a viscous aqueous liquid for introduction into a well penetrating the earth, the method comprising: (a) incorporating a water-dispersible polysaccharide produced by action of the bacterium Xanthomonas campestris on a carbohydrate into an aqueous liquid having a salinity within the range of 0-0.03 weight percent, (b) thereafter incorporating trivalent metal ions selected from the group consisting of aluminum, chromium, and iron ions into said aqueous liquid in a concentration sufficient to effect complexing of said polysaccharide, (c) thereafter adding an aqueous saline makeup solution to said aqueous liquid containing said polysaccharide and said trivalent metal ions to increase the salinity thereof to a value of at least 0.5 weight percent, and (d) thereafter introducing said aqueous liquid into said well.
Claim 22
Dependent Claim
125 words
In a method of preparing a viscous aqueous liquid for introduction into a well penetrating the earth, the method comprising: (a) incorporating a water-dispersible polysaccharide produced by action of the bacterium Xanthomonas campestris on a carbohydrate into an aqueous liquid having a salinity within the range of 0-0.03 weight percent, (b) thereafter incorporating trivalent metal ions selected from the group consisting of aluminum, chromium, and iron ions into said aqueous liquid in a concentration sufficient to effect complexing of said polysaccharide, (c) thereafter adding an aqueous saline makeup solution to said aqueous liquid containing said polysaccharide and said trivalent metal ions to increase the salinity thereof to a value of at least 0.5 weight percent, and (d) thereafter introducing said aqueous liquid into said well.
Claim 23
Dependent Claim
13 words
The method of claim 16 wherein said trivalent metal ions comprise chromium ions.
Claim 24
Dependent Claim
52 words
The method of claim 17 further comprising the step of, subsequent to step (b) and prior to step (c), adding an alkaline agent to said aqueous liquid containing said polysaccharide and trivalent metal ions to increase the pH thereof and thereafter decreasing the pH of said aqueous liquid concomitantly with step (c).
Claim 25
Dependent Claim
47 words
The method of claim 18 wherein the salinity of said aqueous liquid is increased during step (c) to a value of at least 6 weight percent and wherein the pH of said aqueous liquid is decreased during step (c) to a value within the range of 5-7.5.
Claim 26
Dependent Claim
30 words
The method of claim 19 wherein the concentration of chromium ions in said aqueous liquid at the conclusion of step (c) is within the range of 4-25 parts per million.
Claim 27
Dependent Claim
72 words
In the production of oil from subterranean reservoirs by the waterflooding technique wherein an aqueous polysaccharide B-1459 solution is introduced into a well penetrating the earth, the improvement which comprises using an aqueous polysaccharide solution made by prehydrating the polysaccharide in fresh water and then mixing this prehydrated solution with hard water whereby said prehydration step yields a polysaccharide solution in hard water of higher viscosity than hydrating directly in hard water.
Claim 28
Dependent Claim
72 words
In the production of oil from subterranean reservoirs by the waterflooding technique wherein an aqueous polysaccharide B-1459 solution is introduced into a well penetrating the earth, the improvement which comprises using an aqueous polysaccharide solution made by prehydrating the polysaccharide in fresh water and then mixing this prehydrated solution with hard water whereby said prehydration step yields a polysaccharide solution in hard water of higher viscosity than hydrating directly in hard water.
Claim 29
Dependent Claim
22 words
A method as in claim 21 wherein the fresh water contains inorganic ions in concentrations up to about 300 parts per million.
Claim 30
Dependent Claim
22 words
A method as in claim 21 in which the hard water has an inorganic ion content of 6 weight percent or more.
Claim 31
Dependent Claim
48 words
A method as in claim 21 in which trivalent metal ions selected from aluminum, chromium and iron ions are incorporated into the prehydrated solution before the hard water is mixed with it, the trivalent metal ions being used in a concentration sufficient to effect complexing of the polysaccharide.
Claim 32
Dependent Claim
21 words
A method as in claim 24 in which a biocide is incorporated into the solution before the hard water is added.
Claim 33
Dependent Claim
26 words
A method as in claim 24 in which an aqueous solution of an alkaline agent is incorporated into the solution before the hard water is added.
Claim 34
Dependent Claim
31 words
A method as in claim 24 in which the concentration of trivalent metal ions in the solution after the hard water is added is no greater than 25 parts per million.
Claim 35
Dependent Claim
72 words
In the production of oil from subterranean reservoirs by the waterflooding technique wherein an aqueous polysaccharide B-1459 solution is introduced into a well penetrating the earth, the improvement which comprises using an aqueous polysaccharide solution made by prehydrating the polysaccharide in distilled water and then mixing this prehydrated solution with hard water whereby said prehydration step yields a polysaccharide solution in hard water of higher viscosty than hydrating directly in hard water.
Claim 36
Dependent Claim
72 words
In the production of oil from subterranean reservoirs by the waterflooding technique wherein an aqueous polysaccharide B-1459 solution is introduced into a well penetrating the earth, the improvement which comprises using an aqueous polysaccharide solution made by prehydrating the polysaccharide in distilled water and then mixing this prehydrated solution with hard water whereby said prehydration step yields a polysaccharide solution in hard water of higher viscosty than hydrating directly in hard water.
Claim 37
Dependent Claim
89 words
In the production of oil from a subterranean reservoir by the waterflooding technique in which an aqueous liquid comprising a polysaccharide produced by the action of bacteria of the genus Xanthomonas on a carbohydrate is introduced into a well penetrating the earth, the improvement which comprises: using an aqueous polysaccharide solution made by prehydrating the polysaccharide in fresh water and then mixing this prehydrated solution with hard water, whereby the prehydration step yields a polysaccharide solution in hard water of higher viscosity than by hydrating directly in hard water.
Claim 38
Dependent Claim
89 words
In the production of oil from a subterranean reservoir by the waterflooding technique in which an aqueous liquid comprising a polysaccharide produced by the action of bacteria of the genus Xanthomonas on a carbohydrate is introduced into a well penetrating the earth, the improvement which comprises: using an aqueous polysaccharide solution made by prehydrating the polysaccharide in fresh water and then mixing this prehydrated solution with hard water, whereby the prehydration step yields a polysaccharide solution in hard water of higher viscosity than by hydrating directly in hard water.
Claim 39
Dependent Claim
40 words
A method according to claim 29 in which the polysaccharide is prehydrated in fresh water having a salinity of up to 0.03 weight percent and the polysaccharide solution in hard water has a salinity of at least 0.5 weight percent.
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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) | 1989-03-10 | 1989-09-09 | 1990-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-10 | 1993-09-09 | 1994-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-10 | 1997-09-09 | 1998-03-11 | $7700.00 | Window Closed / Lapsed |