Patent DE753345C successfully refreshed from Google Patents.
Patent US3924684A successfully refreshed from Google Patents.
US3924684A
Expired / Lapsed
US
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Method for stimulating well production
Assignee: Texaco Inc
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Filing: 1973-12-20
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Granted: 1975-12-09
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Expires: 1993-12-20
Abstract
Abstract The production of hydrocarbons from a subterranean hydrocarbonbearing formation containing acid-soluble components, such as one containing clays or siliceous minerals as exemplified by sandstone, shale, etc. is stimulated by injecting into the formation a composition comprising an aqueous solution of a mineral acid and a fluorine-containing acid or salt and having dissolved therein a vinylpyrrolidone polymer. The in-depth increase in the permeability and porosity of the formation achieved utilizing the method of invention results in a substantial improvement in hydrocarbon recovery.
Inventors
- 👤 Jack F Tate
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:43
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
144 words
A method of increasing the production of fluids from a subterranean fluid bearing formation having present therein sandstone and clay components comprising injecting down the wellbore penetrating said formation and injecting therefrom into said formation under a pressure greater than the formation pressure an aqueous well acidizing composition comprising an aqueous solution of from 5 to about 12 percent by weight of a mineral acid selected from the group consisting of hydrochloric and sulfuric acid, from about 3 to about 7 percent by weight of hydrofluoric acid and having dissolved therein from about 0.5 to about 5 percent by weight of a vinylpyrrolidone polymer, maintaining said composition in contact with the formation for a time sufficient for the acid to chemically react with the acid-soluble components of the formation to etch passageways therethrough thereby increasing substantially the flow capacity of the said subterranean formation.
Claim 2
Independent Claim
144 words
A method of increasing the production of fluids from a subterranean fluid bearing formation having present therein sandstone and clay components comprising injecting down the wellbore penetrating said formation and injecting therefrom into said formation under a pressure greater than the formation pressure an aqueous well acidizing composition comprising an aqueous solution of from 5 to about 12 percent by weight of a mineral acid selected from the group consisting of hydrochloric and sulfuric acid, from about 3 to about 7 percent by weight of hydrofluoric acid and having dissolved therein from about 0.5 to about 5 percent by weight of a vinylpyrrolidone polymer, maintaining said composition in contact with the formation for a time sufficient for the acid to chemically react with the acid-soluble components of the formation to etch passageways therethrough thereby increasing substantially the flow capacity of the said subterranean formation.
Claim 3
Dependent Claim
13 words
The method of claim 1, wherein the said formation is a hydrocarbon-bearing formation.
Claim 4
Dependent Claim
33 words
The method of claim 1, wherein the said composition is injected down the wellbore penetrating said formation under a pressure greater than the formation pressure and sufficient to create fractures in the formation.
Claim 5
Dependent Claim
37 words
The method of claim 1, wherein the said composition is injected down the wellbore penetrating said formation under a pressure greater than the formation pressure but less than the pressure required to create fractures in the formation.
Claim 6
Independent Claim
103 words
A METHOD OF INCREASING THE PRODUCTION OF FLUIDS FROM A SUBSTERRANEAN FLUID BEARING FORMATION HAVING PERSENT THEREIN SANDSTONE AND CLAY COMPONENTS COMPRISING INJECTING THEREFROM INTO SAID FORMATION UNDER A PRESURE GREATER THAN THE FORMATION PRESSURE AN AQUEOUS WELL ACIDIZING COMPOSITION COMPRISING AN AQUEOUS SOLUTION OF FROM ABOUT 5 TO ABOUT 12 PERCENT BY WEIGHT OF A MINERAL ACID SELECTED FROM THE GROUP CONSISTING OF HYDROCHLORIC AND SULFRIC ACID, FROM ABOUT 3 TO ABOUT 7 PERCENT BY WEIGHT OF HYDROFLUORIC ACID AND HAVING DISSOLVED THEREIN FROM ABOUT 0.5 TO ABOUT 5 PERCENT BY WEIGHT OF A VINYLPYRROLIDONE POLYMER COMPRISING RECURRING UNITS OF THE FORMULA:
Claim 7
Independent Claim
103 words
A METHOD OF INCREASING THE PRODUCTION OF FLUIDS FROM A SUBSTERRANEAN FLUID BEARING FORMATION HAVING PERSENT THEREIN SANDSTONE AND CLAY COMPONENTS COMPRISING INJECTING THEREFROM INTO SAID FORMATION UNDER A PRESURE GREATER THAN THE FORMATION PRESSURE AN AQUEOUS WELL ACIDIZING COMPOSITION COMPRISING AN AQUEOUS SOLUTION OF FROM ABOUT 5 TO ABOUT 12 PERCENT BY WEIGHT OF A MINERAL ACID SELECTED FROM THE GROUP CONSISTING OF HYDROCHLORIC AND SULFRIC ACID, FROM ABOUT 3 TO ABOUT 7 PERCENT BY WEIGHT OF HYDROFLUORIC ACID AND HAVING DISSOLVED THEREIN FROM ABOUT 0.5 TO ABOUT 5 PERCENT BY WEIGHT OF A VINYLPYRROLIDONE POLYMER COMPRISING RECURRING UNITS OF THE FORMULA:
Claim 8
Independent Claim
169 words
A method of increasing the production of fluids from a subterranean fluid-bearing formation having present therein sandstone and clay components comprising injecting down the wellbore penetrating said formation and injecting therefrom into said formation under a pressure greater than the formation pressure an aqueous acidizing composition comprising an acid aqueous solution formed by adding to an aqueous solution of about 10 to about 18 weight percent Of a mineral acid selected from the group consisting of hydrochloric and sulfuric acid from about 0.5 to about 10 percent by weight of a fluorine-containing salt selected from the group consisting of (A) fluorides of the formula: MF, wherein M is selected from the group consisting of NH4 and Li and (B) acid fluorides of the formula: MHF2 wherein M has the same meaning as described above, and having dissolved therein from about 0.5 to about 5 percent by weight of a vinylpyrrolidone polymer having an average molecular weight of about 10,000 to about 1,000,000 and comprising recurring units of the formula:
Claim 9
Independent Claim
169 words
A method of increasing the production of fluids from a subterranean fluid-bearing formation having present therein sandstone and clay components comprising injecting down the wellbore penetrating said formation and injecting therefrom into said formation under a pressure greater than the formation pressure an aqueous acidizing composition comprising an acid aqueous solution formed by adding to an aqueous solution of about 10 to about 18 weight percent Of a mineral acid selected from the group consisting of hydrochloric and sulfuric acid from about 0.5 to about 10 percent by weight of a fluorine-containing salt selected from the group consisting of (A) fluorides of the formula: MF, wherein M is selected from the group consisting of NH4 and Li and (B) acid fluorides of the formula: MHF2 wherein M has the same meaning as described above, and having dissolved therein from about 0.5 to about 5 percent by weight of a vinylpyrrolidone polymer having an average molecular weight of about 10,000 to about 1,000,000 and comprising recurring units of the formula:
Claim 10
Dependent Claim
33 words
The method of claim 6 wherein prior to injecting the said composition into the formation, the formation is pre-flushed with hydrochloric acid having a concentration of about 1 to about 5 weight percent.
Claim 11
Dependent Claim
22 words
The method of claim 6 wherein prior to injecting the said composition into the formation, the formation is preflushed with fresh water.
Claim 12
Dependent Claim
33 words
The method of claim 6 wherein in the composition employed the fluorine-containing salt is a fluoride of the formula: MF, wherein M is selected from the group consisting of NH4 and Li .
Claim 13
Dependent Claim
16 words
The method of claim 6 wherein in the composition employed the fluorine-containing salt is ammonium fluoride.
Claim 14
Dependent Claim
72 words
The method of claim 6 wherein prior to injecting the composition a slug of an aqueous composition containing from about 2.5 to about 10 weight percent of a fluorine containing salt selected from the group consisting of (A) fluorides of the formula: MF, wherein M is selected from the group consisting of NH4 and Li and (B) acid fluorides of the formula: MHF2, wherein M has the same meaning as described above.
Claim 15
Independent Claim
173 words
The method of increasing the production of fluids from a subterranean fluid-bearing formation having present therein sandstone and clay components comprising injecting down the wellbore penetrating said formation and injecting therefrom into said formation under a pressure greater than the formation pressure an aqueous acidizing composition comprising an acid aqueous solution formed by adding to an aqueous solution of about 10 to about 18 weight percent of a mineral acid selected from the group consisting of hydrochloric and sulfuric acid and having dissolved therein, from about 0.5 to about 10 percent by weight of a fluorine-containing salt selected from the group consisting of (A) fluorides of the formula: MF, wherein M is selected from the group consisting of NH4 and Li and (B) acid fluorides of the formula: MHF2 wherein M has the same meaning as described above, and having dissolved therein from about 0.5 to about 5 percent by weight of a vinylpyrrolidone polymer having an average molecular weight of about 10,000 to about 1,000,000 and comprising recurring units of the formula:
Claim 16
Independent Claim
173 words
The method of increasing the production of fluids from a subterranean fluid-bearing formation having present therein sandstone and clay components comprising injecting down the wellbore penetrating said formation and injecting therefrom into said formation under a pressure greater than the formation pressure an aqueous acidizing composition comprising an acid aqueous solution formed by adding to an aqueous solution of about 10 to about 18 weight percent of a mineral acid selected from the group consisting of hydrochloric and sulfuric acid and having dissolved therein, from about 0.5 to about 10 percent by weight of a fluorine-containing salt selected from the group consisting of (A) fluorides of the formula: MF, wherein M is selected from the group consisting of NH4 and Li and (B) acid fluorides of the formula: MHF2 wherein M has the same meaning as described above, and having dissolved therein from about 0.5 to about 5 percent by weight of a vinylpyrrolidone polymer having an average molecular weight of about 10,000 to about 1,000,000 and comprising recurring units of the formula:
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |