US3831679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stimulation with inhibited acidizing fluids
Assignee: Marathon Oil Co
•
Filing: 1973-07-05
•
Granted: 1974-08-27
•
Expires: 1993-07-05
Abstract
Abstract Production and injection wells are stimulated with an inhibited acidizing microemulsion containing hydrocarbon (external phase), surfactant, and acid. The acid is inhibited from reacting with the reservoir rock until it has penetrated the rock face. About 5 - 500 gallons of the microemulsion per vertical foot of formation are useful to stimulate the wells. Carbonate reservoirs are particularly suited for stimulation.
Inventors
- 👤 C Presley
- 👤 R Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:30
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
13 words
The process of claim 1 wherein the hydrocarbon is a substantially paraffinic hydrocarbon.
Claim 2
Dependent Claim
14 words
The process of claim 1 wherein the acid is hydrochloric acid or hydrofluoric acid.
Claim 3
Dependent Claim
23 words
The process of claim 1 wherein the sulfonate is a petroleum sulfonate having an average equivalent weight of about 400 to about 550.
Claim 4
Dependent Claim
20 words
The process of claim 1 wherein about 1% to about 50% of a aliphatic alcohol is incorporated into the microemulsion.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein the formation is a carbonate formation.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein the well is an injection well.
Claim 7
Dependent Claim
19 words
The process of claim 1 wherein water is injected behind the microemulsion to displace it out into the reservoir.
Claim 8
Dependent Claim
85 words
A process of increasing the injectivity index of an injection well in fluid communication with a hydrocarbon-bearing, carbonate formation comprising injecting into the formation about 5 to about 500 gallons of a microemulsion per vertical foot of carbonate formation, the microemulsion being comprised of about 25 to about 75% of a substantially paraffinic hydrocarbon, about 10 to about 40% of a petroleum sulfonate having an average equivalent weight of about 400 to about 550, and about 5% to about 15% of hydrochloric or hydrofluoric acid.
Claim 9
Dependent Claim
28 words
The process of claim 9 wherein about 5% to about 40% of an aliphatic alcohol containing about 3 to about 16 carbon atoms is incorporated into the microemulsion.
Claim 10
Dependent Claim
17 words
The process of claim 9 wherein the microemulsion contains about 35 to about 65% by volume hydrocarbon.
Claim 11
Dependent Claim
15 words
The process of claim 9 wherein the sulfonate concentration is about 20% to about 35%.
Claim 12
Dependent Claim
18 words
The process of claim 9 wherein the acid is hydrochloric acid and contains up to about 38% HCl.
Claim 13
Dependent Claim
21 words
The process of claim 9 wherein the acid is hydrofluoric acid and contains up to about 50% by weight of HF.
Claim 14
Dependent Claim
16 words
The process of claim 9 wherein the microemulsion contains about 6% to about 12.5% of acid.
References Cited (Backward Citations)
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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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |