Patent US3946809A successfully refreshed from Google Patents.
US3946809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oil recovery by combination steam stimulation and electrical heating
Assignee: ExxonMobil Upstream Research Co
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Filing: 1974-12-19
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Granted: 1976-03-30
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Expires: 1994-12-19
Abstract
Abstract Disclosed herein is a method for recovering oil from a subterranean oil-bearing formation in which adjacent wells are subjected to steam stimulation to create a zone around each well which is initially heated to approximately steam temperature and which has a high water saturation following steam injection and oil production. Subsequently, a fluid having a relatively high electrical conductivity, such as a brine solution, is injected into the heated zone around the wells. Preferably the injected volume of high conductivity fluid is sufficient to displace the steam condensate from the zone and to fill the zone with the high conductivity fluid. The wells are then completed as electrodes and current is passed through the formation to heat the oil which was not heated to any significant amount by the steam. Following one or more cycles of steam stimulation and electrical heating, additional oil is recovered from the formation, preferably by line-drive steam displacement or by pattern steam flooding.
Inventors
- 👤 Alton R. Hagedorn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:32
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; E21B43/18; E21B43/2401
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
136 words
A method for recovering oil from a subterranean formation containing oil and connate water and penetrated by a plurality of wells which comprises injecting steam into said formation at each of said wells to heat said formation and said oil contained in said formation, withdrawing heated oil from said formation by means of the same said wells and thereby decreasing the oil saturation in the steam heated portion of said formation and increasing the water saturation within said heated portion of said formation, injecting an electrically conductive fluid into said formation at a volume sufficient to occupy at least a part of the portion of the formation heated by said steam, passing an electrical current between said wells to further heat said formation and said oil contained in said formation, and withdrawing oil from said formation.
Claim 2
Independent Claim
136 words
A method for recovering oil from a subterranean formation containing oil and connate water and penetrated by a plurality of wells which comprises injecting steam into said formation at each of said wells to heat said formation and said oil contained in said formation, withdrawing heated oil from said formation by means of the same said wells and thereby decreasing the oil saturation in the steam heated portion of said formation and increasing the water saturation within said heated portion of said formation, injecting an electrically conductive fluid into said formation at a volume sufficient to occupy at least a part of the portion of the formation heated by said steam, passing an electrical current between said wells to further heat said formation and said oil contained in said formation, and withdrawing oil from said formation.
Claim 3
Dependent Claim
48 words
A method as defined in claim 1 further comprising, subsequent to passing an electrical current between said wells, injecting steam at one of said wells to drive heated oil toward a second of said wells and withdrawing heated oil from said formation by means of said second well.
Claim 4
Dependent Claim
83 words
A method as defined in claim 2 further comprising repeating the steps of injecting steam into said formation at each of said wells, withdrawing oil from said formation by means of the same said wells, injecting an electrically conductive fluid into said formation, and passing an electrical current between said wells prior to injecting steam at one of said wells to drive heated oil toward a second of said wells and withdrawing heated oil from said formation by means of said second well.
Claim 5
Dependent Claim
25 words
A method as defined in claim 1 wherein the electrically conductive fluid is a brine having a higher electrical conductivity than the connate formation water.
Claim 6
Dependent Claim
21 words
A method as defined in claim 4 wherein said brine is heated at the surface prior to injection into said formation.
Claim 7
Dependent Claim
37 words
A method as defined in claim 1 wherein the volume of electrically conductive fluid injected into the formation is sufficient to occupy substantially all of the water saturated portion of the steam heated portion of the formation.
Claim 8
Dependent Claim
27 words
A method as defined in claim 1 wherein steam is injected concurrently into each of said wells to heat said formation and oil contained in said formation.
Claim 9
Dependent Claim
38 words
A method as defined in claim 1 wherein steam is injected into said formation until the steam heated portion of the formation at one well interconnects with the steam heated portion of the formation at a second well.
Claim 10
Dependent Claim
24 words
A method as defined in claim 1 wherein each of said wells is fractured prior to injecting an electrically conductive fluid into said formation.
Claim 11
Dependent Claim
29 words
A method as defined in claim 1 wherein the electric current is passed between said wells by completing said wells as electrodes and applying alternating current between said wells.
Claim 12
Dependent Claim
40 words
A method as defined in claim 1 wherein, during the passage of electrical current between said wells, brine is circulated down each of said wells to cool said wells and to provide electrical contact between said wells and said formation.
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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) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |