US4485871A
Expired / Lapsed
US
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In-situ process for recovering hydrocarbons from a diatomite-type formation
Assignee: Chevron USA Inc
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Filing: 1983-03-09
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Granted: 1984-12-04
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Expires: 2003-03-09
Abstract
Abstract An in-situ process for recovering hydrocarbons from a diatomite-type formation which comprises contacting the diatomite formation with a C 4 -C 10 alcohol and thereafter displacing the hydrocarbon-alcohol mixture with an aqueous alkaline solution towards a production well. The aqueous alkaline solution can be displaced with additional solution or another suitable medium such as a connate water drive.
Inventors
- 👤 Bruce W. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:09
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; C; C09; C09K; C09K8/00; C09K8/58; C09K8/592; C09K8/60
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
83 words
An in-situ sequential process for recovering hydrocarbons from a diatomite formation comprising: (a) injecting a sufficient amount of a slightly soluble in water or insoluble in water C 4 -C 10 alcohol or mixture of alcohols at an injection well to produce a hydrocarbon-alcohol phase at a production well; thereafter, (b) injecting an aqueous alkaline solution into said formation at said injection well; thereafter, (c) displacing said aqueous alkaline solution towards said production well; thereafter, and (d) recovering hydrocarbons from the production well.
Claim 2
Dependent Claim
83 words
An in-situ sequential process for recovering hydrocarbons from a diatomite formation comprising: (a) injecting a sufficient amount of a slightly soluble in water or insoluble in water C 4 -C 10 alcohol or mixture of alcohols at an injection well to produce a hydrocarbon-alcohol phase at a production well; thereafter, (b) injecting an aqueous alkaline solution into said formation at said injection well; thereafter, (c) displacing said aqueous alkaline solution towards said production well; thereafter, and (d) recovering hydrocarbons from the production well.
Claim 3
Dependent Claim
34 words
The process according to claim 1 wherein the C 4 -C 10 alcohol is a C 4 -C 10 straight- or branched-chain aliphatic, alicyclic, aromatic, substituted aromatic, substitued alicyclic, aromatic-alicyclic, olefinic, or mixtures thereof.
Claim 4
Dependent Claim
16 words
The process according to claim 2 wherein the alcohol is a straight-chain or a branched-chain alcohol.
Claim 5
Dependent Claim
17 words
The process according to claim 3 wherein the alcohol is a straight-chain C 4 -C 10 alcohol.
Claim 6
Dependent Claim
23 words
The process according to claim 2 wherein the alcohol is injected in an amount of from about 0.1 to about 1.0 pore volumes.
Claim 7
Dependent Claim
20 words
The process according to claim 5 wherein said alcohol is heated to from about 20° C. to about 95° C.
Claim 8
Dependent Claim
19 words
The process according to claim 6 wherein the aqueous alkaline solution has a pH greater than about pH 9.
Claim 9
Dependent Claim
32 words
The process according to claim 7 wherein the pH is obtained by adding a condensed silicate, a condensed phosphate, a hydroxide, an alkali metal silicate, or mixtures thereof, to an aqueous solution.
Claim 10
Dependent Claim
29 words
The process according to claim 8 wherein said aqueous alkaline solution is injected in an amount of from about 0.1 to about 1.5 pore volumes of said diatomaceous formation.
Claim 11
Dependent Claim
22 words
The process according to claim 9 wherein the aqueous alkaline solution contains from about 1.5 percent to about 4.5 percent sodium meta-silicate.
Claim 12
Dependent Claim
22 words
The process according to claim 9 wherein the aqueous alkaline solution contains from about 2 percent to about 10 percent sodium tetrapyrophosphate.
Claim 13
Dependent Claim
23 words
The process according to claim 9 wherein the aqueous alkaline solution has a temperature of from about 20° C. to about 95° C.
Claim 14
Dependent Claim
28 words
The process according to claim 9 wherein the alcohol is permitted to soak into the formation after injection and prior to the injection of the aqueous alkaline solution.
Claim 15
Dependent Claim
23 words
The process according to claim 13 wherein the said aqueous alkaline solution is displaced towards said production well with additional aqueous alkaline solution.
Claim 16
Dependent Claim
22 words
The process according to claim 13 wherein said aqueous alkaline solution is displaced towards said production well by a suitable steam drive.
Claim 17
Dependent Claim
25 words
The process according to claim 13 wherein a zone of increased permeability is created by fracturing said formation with said C 4 -C 10 alcohol.
Claim 18
Dependent Claim
23 words
The process according to claim 16 wherein said produced hydrocarbon-alcohol phase is separated and said alcohol is re-injected into a different injection well.
Claim 19
Dependent Claim
23 words
The process according to claim 1 which further comprises creating a zone of increased permeability between an injection well and a production well.
Claim 20
Dependent Claim
85 words
An in-situ process for recovering hydrocarbons from a diatomite formation comprising: (a) injecting a sufficient amount of a C 4 -C 10 alcohol or mixture of alcohols at an injection well to produce a hydrocarbon-alcohol phase at a production well; (b) injecting an aqueous alkaline solution into said formation at said injection well, said solution contains from about 2 percent to about 10 percent sodium tetrapyrophosphate; (c) displacing said aqueous alkaline solution towards said production well; and (d) recovering the hydrocarbons from the production well.
Claim 21
Dependent Claim
85 words
An in-situ process for recovering hydrocarbons from a diatomite formation comprising: (a) injecting a sufficient amount of a C 4 -C 10 alcohol or mixture of alcohols at an injection well to produce a hydrocarbon-alcohol phase at a production well; (b) injecting an aqueous alkaline solution into said formation at said injection well, said solution contains from about 2 percent to about 10 percent sodium tetrapyrophosphate; (c) displacing said aqueous alkaline solution towards said production well; and (d) recovering the hydrocarbons from the production well.
Claim 22
Dependent Claim
23 words
The process according to claim 19 which further comprises creating a zone of increased permeability between an injection well and a production well.
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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) | 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 |