US3704751A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for stimulating well production
Assignee: Texaco Inc
•
Filing: 1971-06-21
•
Granted: 1972-12-05
•
Expires: 1991-06-21
Abstract
Abstract The production of hydrocarbons from a subterranean hydrocarbonbearing formation containing acid-soluble components, such as one composed at least in part of dolomite or limestone, is stimulated by injecting into the formation a composition comprising an aqueous solution of a mineral acid having dissolved therein a phosphate ester of prescribed formula. The elimination of plugging of capillary openings within the formation and mineral scale deposition on production equipment due to postprecipitation of dissolved salts subsequent to acidization by means of the said phosphate ester results in a substantial improvement in hydrocarbon recovery.
Inventors
- 👤 Jack F Tate
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:09
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74; C09K8/78; Y; Y10; Y10S; Y10S507/00; Y10S507/927; Y10S507/933
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
28 words
Method as claimed in claim 1 wherein said ester is a monoester of phosphoric acid esterified with an ethoxylated nonylphenol containing from about six to 10 ethoxy groups.
Claim 2
Dependent Claim
28 words
Method as claimed in claim 1 wherein said ester is a diester of phosphoric acid esterified with an ethoxylated nonylphenol containing from about six to 10 ethoxy groups.
Claim 3
Dependent Claim
29 words
Method as claimed in claim 1 wherein said ester is a monoester of phosphoric acid esterified with an ethoxylated C12-C18 alkanol containing from about 6 to 10 ethoxy groups.
Claim 4
Dependent Claim
29 words
Method as claimed in claim 1 wherein said ester is a diester of phosphoric acid esterified with an ethoxylated C12-C18 alkanol containing from about six to 10 ethoxy groups.
Claim 5
Dependent Claim
33 words
Method as claimed in claim 1 wherein said ester is an admixture of a monoester and a diester of phosphoric acid esterified with an ethoxylated nonylphenol containing from six to 10 ethoxy groups.
Claim 6
Dependent Claim
37 words
Method as claimed in claim 1 wherein said ester consists essentially of a mixture of a monoester and a diester of phosphoric acid esterified with an ethoxylated C12-C18 alkanol containing from about six to 10 ethoxy groups.
Claim 7
Dependent Claim
43 words
Method as claimed in claim 1 wherein said ester comprises a mixture of 40 to 60 percent by weight of nonylphenoxypolyethoxyethyl phosphate and 60 to 40 percent by weight of di(nonylphenoxypolyethoxyethyl) phosphate, each polyethoxy moiety containing an average of about five ethoxy groups.
Claim 8
Dependent Claim
25 words
Method as claimed in claim 1 wherein the said ester is present in a concentration of from about 0.3 to about 1.5 percent by weight.
Claim 9
Dependent Claim
13 words
Method as claimed in claim 1 wherein the said acid is hydrochloric acid.
Claim 10
Dependent Claim
13 words
Method as claimed in claim 1 wherein the said acid is sulfuric acid.
Claim 11
Dependent Claim
26 words
Method as claimed in claim 1 wherein the said ester is dissolved in about 5 to about 20 percent by weight solution of the mineral acid.
Claim 12
Dependent Claim
48 words
Method as claimed in claim 1 wherein the said acid is about 5 to about 28 percent by weight hydrochloric acid and the said ester is present in an amount of from about 0.3 to about 1.5 percent by weight, based on the total weight of the composition.
Claim 13
Dependent Claim
14 words
Method as claimed in claim 1 wherein the said formation is a hydrocarbon-bearing formation.
Claim 14
Dependent Claim
36 words
Method as claimed in claim 1 wherein the said aqueous solution is injected down the well bore penetrating said formation under a pressure greater than the formation pressure and sufficient to create fractures in the formation.
Claim 15
Dependent Claim
40 words
Method as claimed in claim 1 wherein the said aqueous solution is injected down the well bore penetrating said formation under a pressure greater than the formation pressure but less than the pressure required to create fractures in the formation.
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) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |