US3918524A
Expired / Lapsed
US
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Fracture acidizing method
Assignee: Halliburton Co
•
Filing: 1974-08-21
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Granted: 1975-11-11
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Expires: 1994-08-21
Abstract
Abstract An improved method of fracture acidizing an underground well formation to create high capacity flow channels therein whereby the acidizing aspect of the treatment is carried out in substantially all portions of fractures created in the formation.
Inventors
- 👤 Gene C Broaddus
- 👤 Sherman E Fredrickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:07
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/25; E21B43/26; E21B43/27; C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
100 words
A METHOD OF ACID TREATING AN UNDEGROUND WELL FORMATION CONTAINING ONE OR MORE FRACTURES COMPRISING: INTRODUCING A PREFLUSH FLUID INTO SAID FRACTURES AND THEREAFTER INTRODUCING INTO SAID FRACTURES AN AQUEOUS ACID SOLUTION HAVING A SPECIFIC GRAVITY LESS THAN THE SPECIFIC GRAVITY OF SAID PREFLUSH FLUID, WHEREIN THE SPECIFIC GRAVITY OF SAID AQUEOUS ACID SOLUTION, WHEN INTRODUCED INTO SAID FRACTURES, IS ADJUSTED SUCH THAT WHEN SAID AQUEOUS ACID SOLUTION IS ABOUT ONE-QUARTER REACTED THE SPECIFIC GRAVITIES OF SAID AQUEOUS ACID SOLUTION AND SAID PREFLUSH FLUID ARE SUBSTANTIALLY EQUAL WHEREBY SAID ACID TREATING IS CONDUCTED OVER THE ENTIRE FACES OF SAID FRACTURES,
Claim 2
Independent Claim
100 words
A METHOD OF ACID TREATING AN UNDEGROUND WELL FORMATION CONTAINING ONE OR MORE FRACTURES COMPRISING: INTRODUCING A PREFLUSH FLUID INTO SAID FRACTURES AND THEREAFTER INTRODUCING INTO SAID FRACTURES AN AQUEOUS ACID SOLUTION HAVING A SPECIFIC GRAVITY LESS THAN THE SPECIFIC GRAVITY OF SAID PREFLUSH FLUID, WHEREIN THE SPECIFIC GRAVITY OF SAID AQUEOUS ACID SOLUTION, WHEN INTRODUCED INTO SAID FRACTURES, IS ADJUSTED SUCH THAT WHEN SAID AQUEOUS ACID SOLUTION IS ABOUT ONE-QUARTER REACTED THE SPECIFIC GRAVITIES OF SAID AQUEOUS ACID SOLUTION AND SAID PREFLUSH FLUID ARE SUBSTANTIALLY EQUAL WHEREBY SAID ACID TREATING IS CONDUCTED OVER THE ENTIRE FACES OF SAID FRACTURES,
Claim 3
Dependent Claim
42 words
The method of claim 1 comprising the additional steps of continuously introducing successive quantities of said preflush fluid and said aqueous acid solution into said fractures whereby said aqueous acid solution is maintained in uniform distribution throughout said fractures while flowing therethrough.
Claim 4
Dependent Claim
13 words
The method of claim 2 wherein said preflush fluid is an aqueous solution.
Claim 5
Dependent Claim
26 words
The method of claim 3 wherein the specific gravity of said preflush fluid at room temperature is in the range of about 1.0 to about 1.4.
Claim 6
Dependent Claim
27 words
The method of claim 4 wherein the specific gravity of said aqueous acid solution at room temperature is in the range of about 1.02 to about 1.34.
Claim 7
Dependent Claim
27 words
The method of claim 5 wherein said aqueous acid solution is selected from the group consisting of hydrochloric acid, hydrochloric acid-organic acid mixtures and metHanol-hydrochloric acid mixtures.
Claim 8
Dependent Claim
24 words
The method of claim 6 wherein said preflush fluid is selected from the group consisting of sodium chloride, calcium chloride and potassium chloride solutions.
Claim 9
Dependent Claim
32 words
The method of claim 7 wherein the viscosity of said preflush fluid is above about 100 centipoises and the viscosity of said aqueous acid solution is considerably less than about 100 centipoises.
Claim 10
Independent Claim
172 words
A method of fracture acidizing an underground well formation so that high capacity flow channels are formed over the entire fractured interval of the formation which comprises the steps of: inducing one or more fractures in said formation, introducing a preflush fluid into said fractures while maintaining the fractures in an open position, and thereafter introducing into said fractures an aqueous acid solution having a specific gravity less than the specific gravity of said preflush fluid, maintaining said fractures in an open position so that said aqueous acid solution is distributed throughout said fractures whereby channels are etched in the faces of said fractures, and causing said fractures to close thereby forming high capacity flow channels therein; wherein the specific gravity of said aqueous acid solution, when introduced into said fractures, is adjusted such that when said aqueous acid solution is about one-quarter reacted the specific gravities of said aqueous acid solution and said preflush fluid are substantially equal whereby said acid treating is conducted over the entire faces of said fractures.
Claim 11
Independent Claim
172 words
A method of fracture acidizing an underground well formation so that high capacity flow channels are formed over the entire fractured interval of the formation which comprises the steps of: inducing one or more fractures in said formation, introducing a preflush fluid into said fractures while maintaining the fractures in an open position, and thereafter introducing into said fractures an aqueous acid solution having a specific gravity less than the specific gravity of said preflush fluid, maintaining said fractures in an open position so that said aqueous acid solution is distributed throughout said fractures whereby channels are etched in the faces of said fractures, and causing said fractures to close thereby forming high capacity flow channels therein; wherein the specific gravity of said aqueous acid solution, when introduced into said fractures, is adjusted such that when said aqueous acid solution is about one-quarter reacted the specific gravities of said aqueous acid solution and said preflush fluid are substantially equal whereby said acid treating is conducted over the entire faces of said fractures.
Claim 12
Dependent Claim
57 words
The method of claim 9 which is further characterized to include the step of continuously introducing successive quantities of said preflush fluid and said aqueous acid solution into said fractures while holding said fractures open so that said aqueous acid solution is maintained distributed throughout said fractures while flowing through said fractures and said fractures are extended.
Claim 13
Dependent Claim
13 words
The method of claim 10 wherein said preflush fluid is an aqueous solution.
Claim 14
Dependent Claim
26 words
The method of claim 11 wherein the specific gravity of said preflush fluid at room temperature is in the range of about 1.0 to about 1.4.
Claim 15
Dependent Claim
27 words
The method of claim 12 wherein the specific gravity of said aqueous acid solution at room temperature is in the range of about 1.02 to about 1.34.
Claim 16
Dependent Claim
27 words
The method of claim 13 wherein said aqueous acid solution is selected from the group consisting of hydrochloric acid, hydrochloric acid-organic acid mixtures and methanol-hydrochloric acid mixtures.
Claim 17
Dependent Claim
24 words
The method of claim 14 wherein said preflush fluid is selected from the group consisting of sodium chloride, calcium chloride and potassium chloride solutions.
Claim 18
Dependent Claim
32 words
The method of claim 15 wherein the viscosity of said preflush fluid is above about 100 centipoises and the viscosity of said aqueous acid solution is considerably less than about 100 centipoises.
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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) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |