US4418752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal oil recovery with solvent recirculation
Assignee: ConocoPhillips Co
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Filing: 1982-01-07
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Granted: 1983-12-06
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Expires: 2002-01-07
Abstract
Abstract A process for the production of heavy oil from a subterranean oil reservoir by the injection of a hot aqueous fluid into the reservoir and the injection of a diluent solvent down the production well to produce a blend of solvent and oil having a decreased viscosity. The reservoir oil has a density greater than the density of water. The diluent solvent has a density such that the density of the resulting blend recovered from the production well also has a density greater than the density of the water. The water produced from the production well is separated from the blend and the blend then fractionated to recover a solvent fraction of the requisite density. This solvent fraction is then returned to the production well to produce additional blend within the well in a continuation of the process.
Inventors
- 👤 Lyndon D. Boyer
- 👤 Ardis L. Anderson
- 👤 Michael W. Britton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:24
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; E21B43/34; E21B43/40
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
162 words
In a method for the recovery of oil from a subterranean reservoir containing oil therein having a density greater than the density of water and penetrated by a production well, wherein a hot aqueous fluid is injected into said reservoir to reduce the viscosity of oil within said reservoir to facilitate the flow of oil into said well and a diluent solvent is circulated down said well to produce a solvent-oil blend of decreased viscosity which is produced from said well in admixture with water, the improvement comprising: (a) employing a diluent having a density such that the density of the resulting oil-solvent blend is greater than the density of the water produced from said well along with said blend, (b) separating said water from said oil-solvent blend, (c) fractionating the oil-solvent blend to recover a solvent fraction having a density as set forth in step (a), and (d) circulating said solvent fraction down said production well in accordance with step (a).
Claim 2
Dependent Claim
162 words
In a method for the recovery of oil from a subterranean reservoir containing oil therein having a density greater than the density of water and penetrated by a production well, wherein a hot aqueous fluid is injected into said reservoir to reduce the viscosity of oil within said reservoir to facilitate the flow of oil into said well and a diluent solvent is circulated down said well to produce a solvent-oil blend of decreased viscosity which is produced from said well in admixture with water, the improvement comprising: (a) employing a diluent having a density such that the density of the resulting oil-solvent blend is greater than the density of the water produced from said well along with said blend, (b) separating said water from said oil-solvent blend, (c) fractionating the oil-solvent blend to recover a solvent fraction having a density as set forth in step (a), and (d) circulating said solvent fraction down said production well in accordance with step (a).
Claim 3
Dependent Claim
30 words
The method of claim 1 wherein the viscosity of said solvent-oil blend at the temperature at which said water separation step is carried out is no greater than 300 cps.
Claim 4
Dependent Claim
30 words
The method of claim 1 wherein the viscosity of said solvent-oil blend at the temperature at which said water separation step is carried out is no greater than 100 cps.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein said solvent has a density which is greater than the density of said water.
Claim 6
Dependent Claim
28 words
The method of claim 1 wherein the density of said oil-solvent blend is greater than the density of said water by an increment of at least 5° API.
Claim 7
Dependent Claim
27 words
The method of claim 5 wherein the density of said solvent is greater than the density of said water by an increment of at least 5° API.
Claim 8
Dependent Claim
33 words
The method of claim 1 wherein said solvent is circulated down said production well at a rate to provide a ratio of solvent to oil in said blend of no greater than 1.
Claim 9
Dependent Claim
35 words
The method of claim 7 wherein said solvent is circulated down said production well at a rate to provide a ratio of solvent to oil in said blend within the range of 0.3 to 1.0.
Claim 10
Dependent Claim
35 words
The method of claim 1 wherein said hot aqueous fluid is steam and further comprising the step of generating said steam by the combustion of a fuel derived from the fractionation of said oil-solvent blend.
Claim 11
Dependent Claim
38 words
The method of claim 1 wherein said blend is fractionated by fractional distillation and said solvent fraction is a gas-oil cut having a viscosity at the temperature circulated down said production well of no greater than 5 centipoises.
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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) | 1986-12-05 | 1987-06-06 | 1987-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-05 | 1991-06-06 | 1991-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-05 | 1995-06-06 | 1995-12-06 | $7700.00 | Window Closed / Lapsed |