US4304677A
Expired / Lapsed
US
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Method of servicing wellbores
Assignee: Dow Chemical Co
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Filing: 1978-09-05
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Granted: 1981-12-08
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Expires: 1998-09-05
Abstract
Abstract The servicing of wellbores with a high density fluid to maintain an elevated pressure on a portion of the formation penetrated by the well is improved. The improvement comprises injecting as the high density fluid a substantially solids-free aqueous solution of calcium bromide and zinc bromide having a density of at least about 15 pounds per gallon. The aqueous solution is prepared by reacting hydrogen bromide with zinc or compounds of zinc in the presence of an aqueous calcium bromide solution.
Inventors
- 👤 Randall C. Stauffer
- 👤 Andrew J. Pasztor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:04
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/16; E; E21; E21B; E21B43/00; E21B43/25; Y; Y10; Y10S; Y10S507/00; Y10S507/925; Y10S507/926
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
58 words
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least about 18 pounds per gallon and a crystallization point of less than about 50° F., prepared by reacting hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide.
Claim 2
Dependent Claim
58 words
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least about 18 pounds per gallon and a crystallization point of less than about 50° F., prepared by reacting hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide.
Claim 3
Dependent Claim
25 words
The composition of claim 1 wherein the calcium bromide is 19.9 to 26 weight percent and the zinc bromide is 46 to 59.6 weight percent.
Claim 4
Dependent Claim
21 words
The composition of claim 2 wherein the ratio of calcium bromide to zinc bromide is from about 0.5:1 to about 0.2:1.
Claim 5
Dependent Claim
65 words
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least about 18 pounds per gallon and a weight ratio of calcium bromide to zinc bromide of from about 0.5:1 to about 0.2:1 prepared by reacting hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide.
Claim 6
Dependent Claim
65 words
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least about 18 pounds per gallon and a weight ratio of calcium bromide to zinc bromide of from about 0.5:1 to about 0.2:1 prepared by reacting hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide.
Claim 7
Dependent Claim
99 words
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least 18 pounds per gallon and a crystallization point of less than about 50° F. prepared by a process comprising: (a) adding a zinc or zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water; (b) adding an excess of hydrogen bromide; (c) adding a sufficient amount of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6.
Claim 8
Dependent Claim
99 words
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least 18 pounds per gallon and a crystallization point of less than about 50° F. prepared by a process comprising: (a) adding a zinc or zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water; (b) adding an excess of hydrogen bromide; (c) adding a sufficient amount of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6.
Claim 9
Dependent Claim
106 words
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least 18 pounds per gallon and a weight ratio of calcium bromide to zinc bromide of from about 0.5:1 to about 0.2:1 prepared by a process comprising: (a) adding a zinc or zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water; (b) adding an excess of hydrogen bromide; (c) adding a sufficient amount of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6.
Claim 10
Dependent Claim
106 words
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least 18 pounds per gallon and a weight ratio of calcium bromide to zinc bromide of from about 0.5:1 to about 0.2:1 prepared by a process comprising: (a) adding a zinc or zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water; (b) adding an excess of hydrogen bromide; (c) adding a sufficient amount of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6.
Claim 11
Dependent Claim
26 words
The composition of claim 5 or 6 wherein zinc oxide is added in step (a) as the zinc compound and in step (c) as the base.
Claim 12
Dependent Claim
56 words
A composition prepared by a process comprising: reacting sufficient amounts of hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide to form a solids free aqueous solution of calcium bromide and zinc bromide having a density of from about 18 pounds per gallon to about 20 pounds per gallon.
Claim 13
Dependent Claim
56 words
A composition prepared by a process comprising: reacting sufficient amounts of hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide to form a solids free aqueous solution of calcium bromide and zinc bromide having a density of from about 18 pounds per gallon to about 20 pounds per gallon.
Claim 14
Dependent Claim
91 words
A composition prepared by a process comprising: (a) adding a zinc or a zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water; (b) adding an excess of hydrogen bromide; and (c) adding sufficient amounts of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6, to form an aqueous solution of calcium bromide and zinc bromide having a density of from about 18 pounds per gallon to about 20 pounds per gallon.
Claim 15
Dependent Claim
91 words
A composition prepared by a process comprising: (a) adding a zinc or a zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water; (b) adding an excess of hydrogen bromide; and (c) adding sufficient amounts of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6, to form an aqueous solution of calcium bromide and zinc bromide having a density of from about 18 pounds per gallon to about 20 pounds per gallon.
Claim 16
Dependent Claim
13 words
The composition of claim 8 having a pH of 5 to about 6.
Claim 17
Dependent Claim
17 words
The composition of claim 8 or 9 having a crystallization point of less than about 50° F.
Claim 18
Dependent Claim
24 words
The composition of claim 8 or 9 having a weight ratio of calcium bromide to zinc bromide of from about 0.5:1 to about 0.2:1.
Claim 19
Dependent Claim
52 words
A process of preparing a high density well-servicing fluid comprising: reacting sufficient amounts of hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide to form an aqueous solution of calcium bromide and zinc bromide having a density at least from about 18 pounds per gallon.
Claim 20
Dependent Claim
52 words
A process of preparing a high density well-servicing fluid comprising: reacting sufficient amounts of hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide to form an aqueous solution of calcium bromide and zinc bromide having a density at least from about 18 pounds per gallon.
Claim 21
Dependent Claim
23 words
The process of claim 13 wherein the zinc compound is selected from the group consisting of zinc carbonate, zinc hydroxide and zinc oxide.
Claim 22
Dependent Claim
12 words
The process of claim 13 wherein the zinc compound is zinc oxide.
Claim 23
Dependent Claim
20 words
The process of claim 13 wherein the reaction is conducted at temperatures of from about 50° to about 150° C.
Claim 24
Dependent Claim
12 words
The process of claim 13 wherein the hydrogen bromide is substantially anhydrous.
Claim 25
Dependent Claim
75 words
In the method of servicing a wellbore with a high density fluid to maintain an elevated pressure on at least a portion of the formation consisting of placing a hydrostatic head on such formations by injecting a high density fluid into the borehole, the improvement comprising: injecting as the high density fluid a substantially solids-free aqueous solution consisting essentially of a solution of calcium bromide and zinc bromide prepared by the process of claim 5.
Claim 26
Dependent Claim
18 words
The method of claim 18 wherein the solution has a crystallization point of less than about 50° F.
Claim 27
Dependent Claim
93 words
A process for preparing a high density well-servicing fluid comprising: (a) adding zinc or a zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water; (b) adding an excess of hydrogen bromide; and (c) adding sufficient amount of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6, to form an aqueous solution of calcium bromide and zinc bromide having a density of from about 18 pounds per gallon to about 20 pounds per gallon.
Claim 28
Dependent Claim
93 words
A process for preparing a high density well-servicing fluid comprising: (a) adding zinc or a zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water; (b) adding an excess of hydrogen bromide; and (c) adding sufficient amount of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6, to form an aqueous solution of calcium bromide and zinc bromide having a density of from about 18 pounds per gallon to about 20 pounds per gallon.
Claim 29
Dependent Claim
15 words
The process of claim 20 wherein the zinc material and the base are zinc oxide.
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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) | 1984-12-07 | 1985-06-08 | 1985-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-07 | 1989-06-08 | 1989-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-07 | 1993-06-08 | 1993-12-08 | $7700.00 | Window Closed / Lapsed |