US3879177A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inhibition of wax crystallization
Assignee: Mobil Oil AS
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Filing: 1973-01-08
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Granted: 1975-04-22
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Expires: 1993-01-08
Abstract
Abstract This specification discloses a process for inhibiting the crystallization of wax in a well from a waxy crude oil produced from a subterranean formation through the well. The process involves addition to the crude oil in the well, upon flowing from the subterranean formation, of an agent which is a copolymer of maleic anhydride and vinyl methyl ether esterified with an alcohol containing 18 to 24 carbon atoms.
Inventors
- 👤 Jr Harry J Andress
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:51
CPC Classifications
C; C10; C10L; C10L1/00; C10L1/10; C10L1/14; C10L1/18; C10L1/192; C10L1/195; C10L1/196; C10L1/1966; C09; C09K; C09K8/00; C09K8/52; C09K8/524
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
75 words
IN A PROCESS FOR THE PRODUCTION OF A WAXY CRUDE OIL FROM A SUBTERRANEAN FORMATION THROUGH A WELL LEADING FROM SAID FORMATION TO THE SURFACE OF THE EARTH, THE STEP FOR INHIBITING CRYSTALLIZATION OF WAX FROM SAID CRUDE OIL COMPRISING MIXING WITH SAID WAXY CRUDE OIL IN SAID WELL ABOUT 6 TO 2500 PARTS PER MILLION BY WEIGHT OF AN AGENT PREPARED BY ESTERIFYING A COPOLYMER OF MALEIC ANHYDRIDE AND VINYL METHYL ETHER WITH DOCOSANOL.
Claim 2
Dependent Claim
75 words
IN A PROCESS FOR THE PRODUCTION OF A WAXY CRUDE OIL FROM A SUBTERRANEAN FORMATION THROUGH A WELL LEADING FROM SAID FORMATION TO THE SURFACE OF THE EARTH, THE STEP FOR INHIBITING CRYSTALLIZATION OF WAX FROM SAID CRUDE OIL COMPRISING MIXING WITH SAID WAXY CRUDE OIL IN SAID WELL ABOUT 6 TO 2500 PARTS PER MILLION BY WEIGHT OF AN AGENT PREPARED BY ESTERIFYING A COPOLYMER OF MALEIC ANHYDRIDE AND VINYL METHYL ETHER WITH DOCOSANOL.
Claim 3
Dependent Claim
76 words
In a process for the production of a waxy crude oil from a subterranean formation through a well leading from said formation to the surface of the earth, the step for inhibiting crystallization of wax from said waxy crude oil comprising mixing with said waxy crude oil in said well about 6 to 2500 parts per million by weight of an agent prepared by esterifying a copolymer of maleic anhydride and vinyl methyl ether with docosanol.
Claim 4
Dependent Claim
76 words
In a process for the production of a waxy crude oil from a subterranean formation through a well leading from said formation to the surface of the earth, the step for inhibiting crystallization of wax from said waxy crude oil comprising mixing with said waxy crude oil in said well about 6 to 2500 parts per million by weight of an agent prepared by esterifying a copolymer of maleic anhydride and vinyl methyl ether with docosanol.
Claim 5
Dependent Claim
21 words
The process of claim 1 wherein said copolymer is esterified with a mixture of alcohols containing 18 to 24 carbon atoms.
Claim 6
Dependent Claim
21 words
The process of claim 1 wherein said agent is in solution in a solvent upon mixing with said waxy crude oil.
Claim 7
Dependent Claim
10 words
The process of claim 3 wherein said solvent is xylene.
Claim 8
Dependent Claim
21 words
The process of claim 3 wherein said agent is in solution in said solvent in a concentration of 5-25% by weight.
Claim 9
Dependent Claim
21 words
The process of claim 3 wherein said agent is in solution in said solvent in a concentration of 10-15% by weight.
Claim 10
Dependent Claim
25 words
The process of claim 1 wherein said agent is mixed with said oil in an amount of 6 to 30 parts per million by weight.
Claim 11
Dependent Claim
23 words
The process of claim 1 wherein said agent is mixed with said oil in an amount of 18 parts per million by weight.
Claim 12
Dependent Claim
19 words
The process of claim 1 wherein each mole of said copolymer is esterified with one mole of said alcohol.
Claim 13
Dependent Claim
19 words
The process of claim 1 wherein each mole of said copolymer is esterified with two moles of said alcohol.
Claim 14
Dependent Claim
37 words
The process of claim 1 wherein said agent is mixed with said waxy crude oil in said well by passing said agent into said well through the annulus between the casing and the tubing of said well.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |