US4485873A
Expired / Lapsed
US
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Process for oil recovery from a subterranean reservoir
Assignee: Huels AG
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Filing: 1982-09-01
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Granted: 1984-12-04
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Expires: 2002-09-01
Abstract
Abstract A process for the recovery of extensively emulsion-free oil from a subterranean reservoir of medium or high salinity comprises forcing into an injection well a 0.1-20% (e.g., 1-20%) by weight solution or dispersion in formation water of carboxymethylated ethoxylates of the formula R--(OCH.sub.2 CH.sub.2).sub.n --OCH.sub.2 --COOM, wherein R is a linear or branched aliphatic residue of 4-20 carbon atoms or an alkylaromatic or dialkylaromatic residue of 1-14 carbon atoms in the alkyl group, n is 1-30, e.g., 3-30, and M is an alkali or alkaline earth metal ion or ammonium, and the degree of carboxymethylation is between 10 and 100%, wherein the carboxymethylated oxethylate is selected so that the phase inversion temperature of the system: crude oil/formation water/tenside/optional additives, is 0°-10° C. above the reservoir temperature.
Inventors
- 👤 Dieter Balzer
- 👤 Kurt Kosswig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:56
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/584; Y; Y10; Y10S; Y10S507/00; Y10S507/935; Y10S507/936
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
138 words
A process for recovering extensively emulsion-free crude oil from a subterranean deposit of medium or high salinity, comprising injecting into an injection well therein, a tenside solution or dispersion in formation water comprising 0.1-20 wt% of a mixture of 0-90 wt % of ethoxylates of the formula: R--(OCH.sub.2 CH.sub.2).sub.n OH and 100-10 wt % of carboxymethylated ethoxylates of the formula: R--(OCH.sub.2 CH.sub.2).sub.n --OCH.sub.2 --COOM wherein R is a hydrocarbon aliphatic group of 4-20 carbon atoms or a mono- or dialkylphenyl group of 1-14 carbon atoms in the alkyl group, n is 1-30, and M is an alkali or alkaline earth metal ion or ammonium, wherein the tenside is selected so that the phase inversion temperature and recovering said extensively emulsion-free crude oil from said deposit of the system: crude oil/formation water/tenside, lies 0°-10° C. above the deposit temperature.
Claim 2
Dependent Claim
138 words
A process for recovering extensively emulsion-free crude oil from a subterranean deposit of medium or high salinity, comprising injecting into an injection well therein, a tenside solution or dispersion in formation water comprising 0.1-20 wt% of a mixture of 0-90 wt % of ethoxylates of the formula: R--(OCH.sub.2 CH.sub.2).sub.n OH and 100-10 wt % of carboxymethylated ethoxylates of the formula: R--(OCH.sub.2 CH.sub.2).sub.n --OCH.sub.2 --COOM wherein R is a hydrocarbon aliphatic group of 4-20 carbon atoms or a mono- or dialkylphenyl group of 1-14 carbon atoms in the alkyl group, n is 1-30, and M is an alkali or alkaline earth metal ion or ammonium, wherein the tenside is selected so that the phase inversion temperature and recovering said extensively emulsion-free crude oil from said deposit of the system: crude oil/formation water/tenside, lies 0°-10° C. above the deposit temperature.
Claim 3
Dependent Claim
19 words
A process of claim 1, wherein the tenside solution or dispersion further comprises a mono-, di-, or trihydric alcohol.
Claim 4
Dependent Claim
23 words
A process of claim 1, wherein the phase inversion temperature of the system: crude oil/formation water/tenside, lies 1°-5° C. above the deposit temperature.
Claim 5
Dependent Claim
18 words
A process of claim 1 wherein water soluble alkaline earth metal salts are added into the formation water.
Claim 6
Dependent Claim
24 words
A process of claim 1 wherein, prior to injecting the tenside solution or dispersion, 0.01-4 PV of formation water is injected into the deposit.
Claim 7
Dependent Claim
24 words
A process of claim 1 wherein, after injection of the tenside solution or dispersion, 0.01-4 PV of formation water is forced into the deposit.
Claim 8
Dependent Claim
17 words
A process of claim 6, wherein said formation water forced into said deposit contains a viscosity-raising polymer.
Claim 9
Dependent Claim
18 words
A process of claim 1 wherein the tenside mixture contains 30% to 90 wt % of carboxymethylated ethoxylates.
Claim 10
Dependent Claim
18 words
A process of claim 1 wherein the tenside mixture contains 50% to 85 wt % of carboxymethylated ethoxylates.
Claim 11
Dependent Claim
18 words
A process of claim 1 wherein the tenside mixture contains 10% to 90 wt % of carboxymethylated ethoxylates.
Claim 12
Dependent Claim
19 words
A process of claim 1 wherein the tenside mixture contains 50% to 100 wt % of of carboxymethylated ethoxylates.
Claim 13
Dependent Claim
17 words
A process of claim 1, wherein the phase inversion temperature lies 1°-10° C. above the deposit temperature.
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) | 1987-12-04 | 1988-06-04 | 1988-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-04 | 1992-06-04 | 1992-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-04 | 1996-06-04 | 1996-12-04 | $7700.00 | Window Closed / Lapsed |