US5515919A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Enhanced oil recovery process including the simultaneous injection of a miscible gas and water
Assignee: Chevron USA Inc
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Filing: 1994-07-01
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Granted: 1996-05-14
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Expires: 2014-07-01
Abstract
Abstract An enhanced oil recovery process comprises of the at least periodic introduction of (i) a non-condensible gas preferably selected from among carbon dioxide, nitrogen, methane or mixtures thereof, and (ii) an aqueous drive solution, preferably brine, into a reservoir formation. In this process, the half cycle of non-condensible gas injection, prior to aqueous drive fluid injection, measured in hydrocarbon pore volume is less than 0.25%. In this preferred embodiment, the non-condensible gas, e.g., carbon dioxide, and water, are simultaneously injected into the formation.
Inventors
- 👤 Chris E. Stevens
- 👤 Steven D. McPherson
- 👤 John R. Larson
- 👤 Donnell R. Robie
- 👤 Ronald K. Wackowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:17
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/594; E; E21; E21B; E21B43/00; E21B43/16; E21B43/164
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
105 words
A process for the enhanced recovery of oil from an oil-bearing reservoir formation comprising at least periodically sequentially injecting effective oil producing amounts of (i) a non-condensible gas and (ii) an aqueous drive fluid into the formation characterized in that the gas and aqueous drive fluid are injected at a preselected water to gas ratio and the amount of gas injected prior to switching to injection of aqueous drive fluid as measured in hydrocarbon pore volume, is less than 0.25% wherein the amount of said gas injected is effective to reduce the viscosity of the oil or to increase its mobility through the reservoir formation.
Claim 2
Dependent Claim
105 words
A process for the enhanced recovery of oil from an oil-bearing reservoir formation comprising at least periodically sequentially injecting effective oil producing amounts of (i) a non-condensible gas and (ii) an aqueous drive fluid into the formation characterized in that the gas and aqueous drive fluid are injected at a preselected water to gas ratio and the amount of gas injected prior to switching to injection of aqueous drive fluid as measured in hydrocarbon pore volume, is less than 0.25% wherein the amount of said gas injected is effective to reduce the viscosity of the oil or to increase its mobility through the reservoir formation.
Claim 3
Dependent Claim
19 words
The process according to claim 1, wherein the non-condensible gas is selected from among carbon dioxide, nitrogen, and methane.
Claim 4
Dependent Claim
13 words
The process according to claim 1, wherein the non-condensible gas is carbon dioxide.
Claim 5
Dependent Claim
13 words
The process according to claim 1, wherein the aqueous drive solution is brine.
Claim 6
Dependent Claim
19 words
The process according to claim 1, wherein the non-condensible gas is carbon dioxide, and the drive fluid is brine.
Claim 7
Dependent Claim
17 words
The process according to claim 1, having a water to gas ratio of between 1:1 and 5:1.
Claim 8
Dependent Claim
83 words
In an enhanced oil recovery process including at least periodic injection of (i) a non-condensible gas and (ii) an aqueous drive fluid into a reservoir formation, wherein the improvement comprises injecting (i) and (ii) simultaneously into the reservoir formation wherein the amount of non-condensible gas injected as, measured in hydrocarbon pore volume, is less than 0.25% and wherein the amount of said non-condensible gas injected is effective to reduce the viscosity of the oil or to increase its mobility through the reservoir formation.
Claim 9
Dependent Claim
83 words
In an enhanced oil recovery process including at least periodic injection of (i) a non-condensible gas and (ii) an aqueous drive fluid into a reservoir formation, wherein the improvement comprises injecting (i) and (ii) simultaneously into the reservoir formation wherein the amount of non-condensible gas injected as, measured in hydrocarbon pore volume, is less than 0.25% and wherein the amount of said non-condensible gas injected is effective to reduce the viscosity of the oil or to increase its mobility through the reservoir formation.
Claim 10
Dependent Claim
18 words
The process according to claim 7, wherein the non-condensible gas comprises carbon dioxide, nitrogen, methane or mixtures thereof.
Claim 11
Dependent Claim
13 words
The process according to claim 7, wherein the non-condensible gas is carbon dioxide.
Claim 12
Dependent Claim
13 words
The process according to claim 7, wherein the aqueous drive fluid is brine.
Claim 13
Dependent Claim
17 words
The process according to claim 7, having a water to gas ratio of between 1:1 and 5:1.
Claim 14
Dependent Claim
21 words
The process according to claim 1, wherein the water to gas ratio decreases from a preselected ratio to a lower ratio.
Claim 15
Dependent Claim
21 words
The process according to claim 7, wherein the water to gas ratio decreases from a preselected ratio to a lower ratio.
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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) | 1999-05-14 | 1999-11-13 | 2000-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-14 | 2003-11-13 | 2004-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-14 | 2007-11-13 | 2008-05-14 | $7700.00 | Window Closed / Lapsed |