US3734186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for acidizing subterranean formations
Assignee: Exxon Mobil Corp
•
Filing: 1971-03-25
•
Granted: 1973-05-22
•
Expires: 1991-03-25
Abstract
Abstract A method for acidizing a carbonate formation surrounding a well wherein a treating fluid containing an acid which on reaction with the carbonate rock forms a soluble salt and an organic acid which on reaction with the carbonate rock forms an insoluble salt is injected into the formation. An afterflush fluid is then injected into the formation to remove the insoluble salt.
Inventors
- 👤 B Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:43
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74; C09K8/78
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
22 words
A method as defined in claim 1 wherein said aqueous fluid is injected at pressures below the fracturing pressure of said formation.
Claim 2
Dependent Claim
35 words
A method as defined in claim 1 wherein the weight concentration of said first acid in said aqueous fluid is greater than the weight concentration of said alkyl aryl sulfonic acid in said aqueous fluid.
Claim 3
Dependent Claim
27 words
A method as defined in claim 1 wherein said alkyl aryl sulfonic acid is alkylbenzenesulfonic acid wherein the alkyl group contains from eight to 18 carbon atoms.
Claim 4
Dependent Claim
14 words
A method as defined in claim 4 wherein the alkylbenZenesulfonic acid is dodecylbenzenesulfonic acid.
Claim 5
Dependent Claim
34 words
A method as defined in claim 1 and further comprising injecting an afterflush fluid into said formation for removing portions of said precipitate from said formation, said afterflush fluid including an organic polar compound.
Claim 6
Dependent Claim
15 words
A method as defined in claim 6 wherein the organic polar compound is an alcohol.
Claim 7
Dependent Claim
14 words
A method as defined in claim 1 wherein said first acid is hydrochloric acid.
Claim 8
Dependent Claim
33 words
A method as defined in claim 8 wherein the concentration of said hydrochloric acid in said aqueous fluid is greater than the concentration of said alkyl aryl sulfonic acid in said aqueous fluid.
Claim 9
Independent Claim
82 words
A method for acidizing a subterranean carbonate formation surrounding a wellbore which comprises injecting into said formation a hydrochloric acid solution containing from about 1 to about 10 percent by weight of an alkyl aryl sulfonic acid which reacts with the carbonate formation to form an acid insoluble precipitate, an alkyl group of said alkyl aryl sulfonic acid containing at least five carbon atoms; and thereafter injecting an afterflush fluid into said formation for removing portions of said precipitate from said formation.
Claim 10
Dependent Claim
26 words
A method as defined in claim 10 wherein the alkyl group of the alkyl aryl sulfonic acid contains between 8 and 18 carbon atoms per molecule.
Claim 11
Dependent Claim
16 words
A method as defined in claim 10 wherein the alkyl aryl sulfonic acid is dodecylbenzenesulfonic acid.
Claim 12
Dependent Claim
27 words
A method as defined in claim 10 wherein said afterflush fluid is capable of dissolving the reaction products of said alkyl aryl sulfonic acid and carbonate formation.
Claim 13
Dependent Claim
35 words
A method as defined in claim 10 wherein the hydrochloric acid solution further contains an effective amount of a low molecular weight sulfonic acid capable of improving the solubility of said alkyl aryl sulfonic acid.
Claim 14
Dependent Claim
18 words
A method as defined in claim 14 wherein said low molecular weight sulfonic acid is p-toluene sulfonic acid.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |