US4096914A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acidizing asphaltenic oil reservoirs with acids containing salicylic acid
Assignee: Shell USA Inc
•
Filing: 1976-12-06
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Granted: 1978-06-27
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Expires: 1996-12-06
Abstract
Abstract A reservoir which contains an asphaltenic oil can be acidized with an aqueous acid without causing a deposition of permeability impairing iron-asphaltene compounds by dissolving or dispersing an effective amount of salicylic acid within at least the first injected portion of the aqueous acid.
Inventors
- 👤 William A. McLaughlin
- 👤 Edwin A. Richardson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:54
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74; C09K8/78; Y; Y10; Y10S; Y10S507/00; Y10S507/927; Y10S507/929; Y10S507/93; Y10S507/933; Y10S507/934
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
111 words
In a well treating process in which an aqueous hydrochloric acid-containing acid capable of dissolving solids in a manner increasing the permeability of a subterranean earth formation is brought into successive contacts with iron and an asphaltene-containing oil that is present within a subterreanean reservoir in a manner that may form permeability impairing iron-asphaltene solids, the improvement which comprises, including within at least the first portion of the aqueous hydrochloric acid-containing acid, a solution or homogeneous dispersion of at least enough salicylic acid to chelate with and prevent the formation of iron-asphaltene solids by substantially all of the ferric ions that become dissolved within the acid that enters the earth formation.
Claim 2
Dependent Claim
111 words
In a well treating process in which an aqueous hydrochloric acid-containing acid capable of dissolving solids in a manner increasing the permeability of a subterranean earth formation is brought into successive contacts with iron and an asphaltene-containing oil that is present within a subterreanean reservoir in a manner that may form permeability impairing iron-asphaltene solids, the improvement which comprises, including within at least the first portion of the aqueous hydrochloric acid-containing acid, a solution or homogeneous dispersion of at least enough salicylic acid to chelate with and prevent the formation of iron-asphaltene solids by substantially all of the ferric ions that become dissolved within the acid that enters the earth formation.
Claim 3
Dependent Claim
25 words
The process of claim 1 in which the salicylic acid-containing portion of the aqueous acid is mixed with a liquid solvent for an asphaltenic oil.
Claim 4
Dependent Claim
30 words
The process of claim 2 in which the oil solvent comprises an aromatic liquid hydrocarbon which is dispersed within the aqueous acid and an oil phase of an oil-in-water emulsion.
Claim 5
Dependent Claim
29 words
The process of claim 1 in which the salicylic acid-containing aqueous acid is flowed into the subterranean earth formation during the course of a fracture-acidizing treatment of the well.
Claim 6
Dependent Claim
36 words
The process of claim 1 in which the flowing of the salicylic acid-containing aqueous acid into the subterranean earth formation is preceded by flowing a slug of liquid solvent for an asphaltenic oil into that formation.
Claim 7
Dependent Claim
53 words
The process of claim 1 in which the aqueous acid contains both hydrochloric and hydrofluoric acid and is a mud acid and the flowing of the salicylic acid-containing portion of the mud acid into the reservoir is preceded by the flowing into the reservoir of a salicylic acid-containing portion of aqueous hydrochloric acid.
Claim 8
Dependent Claim
43 words
The process of claim 1 in which the salicylic acid is included in the first injected portion of the aqueous acid by mixing it with that portion in the form of a substantially dry solid or relatively concentrated aqueous solution of ammonium salicylate.
Claim 9
Dependent Claim
41 words
The process of claim 7 in which the ammonium salicylate is mixed with the aqueous acid along with a liquid oil solvent and the mixture is agitated to form a relatively homogeneous oil-in-water dispersion of oil solvent within the aqueous acid.
Claim 10
Dependent Claim
30 words
The process of claim 1 in which the injecting of the salicylic acid-containing portion of aqueous acid is preceded by injecting a slug of an aqueous solution of ammonium salicylate.
Claim 11
Dependent Claim
24 words
The process of claim 9 in which the injection of the ammonium salicylate solution is preceded by injecting a slug of liquid oil solvent.
References Cited (Backward Citations)
US2175095A
Cited
US2301875A
Cited
US2335689A
Cited
US2885004A
Cited
US3142335A
Cited
US3625284A
Cited
US3799266A
Cited
US3970148A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |