US3793209A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Organic deposit and calcium sulfate scale removal emulsion and process
Assignee: Schlumberger Technology Corp
•
Filing: 1971-08-09
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Granted: 1974-02-19
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Expires: 1991-08-09
Abstract
Abstract An emulsion which is successful for removing calcium sulfate deposits which are coated and/or commingled with an organic deposit is disclosed and claimed. The emulsion comprises a continuous aqueous phase of at least one of sodium citrate, a water soluble salt of ethylenediaminetetraacetic acid, or potassium glycolate, having dispersed therein an aromatic solvent and, as an emulsifier, an acid phosphate ester.
Inventors
- 👤 J Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:27
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12; C09; C09K; C09K8/00; C09K8/52; C09K8/528; Y; Y10; Y10S; Y10S507/00; Y10S507/927
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
25 words
The composition of claim 1 wherein the volume proportion of the aqueous phase to aromatic solvent phase ranges from about 80: 20 to about 50:50.
Claim 2
Dependent Claim
12 words
The composition of claim 1 wherein the scale solvent is tetrasodium ethylenediaminetetraacetate.
Claim 3
Dependent Claim
11 words
The composition of claim 4 wherein the aromatic solvent is toluene.
Claim 4
Independent Claim
128 words
A method of dissolving calcium sulfate scales occluded with organic materials which comprises: a. contacting said scales with an emulsion comprising as the continuous phase an aqueous solution of a calcium sulfate scale solvent selected from the group consisting of an ethylenediaminetetraacetic acid salt, sodium citrate, or potassium glycolate, as the dispersed phase an aromatic solvent for said organic material, said volume proportion of said aqueous phase to said aromatic phase ranging from about 80:20 to about 50:50, and an effective amount of an emulsifier consisting of at least one of a phosphate ester of an ethoxylated straight chain alcohol containing 8 to 10 carbon atoms and containing 4 moles of ethylene oxide, or a phosphate ester of an ethoxylated tridecyl alcohol containing 6 moles of ethylene oxide.
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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) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |