US3847219A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Producing oil from tar sand
Assignee: Shell Canada Ltd
•
Filing: 1973-10-03
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Granted: 1974-11-12
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Expires: 1993-10-03
Abstract
Abstract In a tar sand formation in which a relatively water-impermeable zone overlies a water-permeable zone, tar is recovered by injecting steam into the permeable zone to establish a hot, water-permeable channel between at least one production and at least one injection well, said channel preferably having a tar mobility of at least 15 md/cp; continuing steam injection at a rate sufficient to maintain mobility of the tar in the channel at 15 md/cp and increase the tar mobility in the bulk of the formation to about 15 md/cp, preferably while at about the same time restricting production of fluids from the production well; decreasing the pressure in the formation by increasing production from the production well; and recovering the bitumen from the fluids produced.
Inventors
- 👤 K Wang
- 👤 M Prats
- 👤 D Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:19
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/18; E21B43/24
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
166 words
A PROCESS FOR RECOVERING BITUMINOUS FLUID FROM A BITUMINOUS SAND FORMATION WHICH CONTAINS AT LEAST ONE WATERPERMEABLE ZONE AND AT LEAST ONE ADJACENT, WATER-IMPERMEABLE ZONE AND WHICH HAS BEEN PENETRATED BY AT LEAST ONE INJECTION WELL AND AT LEAST ONE PRODUCTION WELL, BOTH OF WHICH COMMUNICATE WITH SAID WATER-PERMEABLE ZONE, SAID PROCESS COMPRISING: A. INJECTING A HOT AQUEOUS FLUID INTO SAID FORMATION THROUGH AT LEAST ONE WELL WHILE PRODUCING FLUIDS AT AT LEAST ONE OTHER WELL TO ESTABLISH A HOT, WATER-PERMEABLE CHANNEL EXTENDING BETWEEN THE INJECTION AND PRODUCTION WELLS; B. CONTINUING THE INJECTION OF SAID HOT AQUEOUS FLUID AT A RATE AT LEAST SUFFICIENT TO MAINTAIN SAID BITUMINOUS FLUID MOBILITY WITHIN SAID CHANNEL AND TO INCREASE THE MOBILITY OF THE BITUMINOUS FLUID IN THE BULK OF THE BITUMINOUS SAND FORMATION SURROUNDING SAID PATH TO AT LEAST 15 MILLIDARCIES PER CENTIPOISE; C. REDUCING THE PRESSURE IN SAID FORMATION BY INCREASING THE PRODUCTION OF FLUIDS AT THE PRODUCTION WELL; AND D. RECOVERING BITUMINOUS FLUID FROM THE FLUIDS PRODUCED.
Claim 2
Dependent Claim
166 words
A PROCESS FOR RECOVERING BITUMINOUS FLUID FROM A BITUMINOUS SAND FORMATION WHICH CONTAINS AT LEAST ONE WATERPERMEABLE ZONE AND AT LEAST ONE ADJACENT, WATER-IMPERMEABLE ZONE AND WHICH HAS BEEN PENETRATED BY AT LEAST ONE INJECTION WELL AND AT LEAST ONE PRODUCTION WELL, BOTH OF WHICH COMMUNICATE WITH SAID WATER-PERMEABLE ZONE, SAID PROCESS COMPRISING: A. INJECTING A HOT AQUEOUS FLUID INTO SAID FORMATION THROUGH AT LEAST ONE WELL WHILE PRODUCING FLUIDS AT AT LEAST ONE OTHER WELL TO ESTABLISH A HOT, WATER-PERMEABLE CHANNEL EXTENDING BETWEEN THE INJECTION AND PRODUCTION WELLS; B. CONTINUING THE INJECTION OF SAID HOT AQUEOUS FLUID AT A RATE AT LEAST SUFFICIENT TO MAINTAIN SAID BITUMINOUS FLUID MOBILITY WITHIN SAID CHANNEL AND TO INCREASE THE MOBILITY OF THE BITUMINOUS FLUID IN THE BULK OF THE BITUMINOUS SAND FORMATION SURROUNDING SAID PATH TO AT LEAST 15 MILLIDARCIES PER CENTIPOISE; C. REDUCING THE PRESSURE IN SAID FORMATION BY INCREASING THE PRODUCTION OF FLUIDS AT THE PRODUCTION WELL; AND D. RECOVERING BITUMINOUS FLUID FROM THE FLUIDS PRODUCED.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the highest practical injection rates are maintained until said hot, water-permeable channel is established.
Claim 4
Dependent Claim
32 words
The process of claim 2 wherein the rate of production of fluids at the production well is substantially restricted after said hot channel has been established between said injection and production wells.
Claim 5
Dependent Claim
44 words
The process of claim 2 wherein before said hot channel is established the back pressure of the well through which fluids are being produced is maintained at a low value to promote a high rate of growth of said channel in the permeable zone.
Claim 6
Dependent Claim
14 words
The process of claim 1 wherein said water-impermeable zone lies above said water-permeable zone.
Claim 7
Dependent Claim
12 words
The process of claim 1 wherein said hot aqueous fluid is steam.
Claim 8
Dependent Claim
18 words
The process of claim 6 wherein the highest practical injection rates are maintained until said channel is established.
Claim 9
Dependent Claim
41 words
The process of claim 7 wherein before said channel is established, the back pressure of the well through which fluids are being produced is maintained at a low value to promote a high rate of steam advance in the permeable zone.
Claim 10
Dependent Claim
19 words
The process of claim 7 wherein steam is first injected through the production well to establish said hot channel.
Claim 11
Dependent Claim
56 words
The process of claim 9 wherein a steam front moves through the permeable zone to force the in-place water From the formation out the injection well, and, before said steam front reaches the injection well, water production from the injection well is stopped and steam is then injected through the injection well to said permeable zone.
Claim 12
Dependent Claim
36 words
The process of claim 10 wherein steam is injected through said injection well when said steam front has advanced about 50 to 90 per cent of the distance between said production well and said injection well.
Claim 13
Dependent Claim
30 words
The process of claim 8 wherein the rate of production of fluids from the well from which fluids are being produced is substantially restricted shortly after said channel is established.
Claim 14
Dependent Claim
78 words
The process of claim 12 wherein the rate of steam injection is maintained at substantially the same rate as step (a) until mobility value of at least 15 millidarcies/centipoise for said bituminous fluid in said permeable zone is attained, then the rate of injection is decreased to a rate sufficient to maintain said mobility value for the tar in said permeable zone and increase the mobility of the tar in the bulk of the formation to 15 millidarcies/centipoise.
Claim 15
Dependent Claim
22 words
The process of claim 13 wherein the decreased rate of steam injection is maintained for about six months to about three years.
Claim 16
Dependent Claim
34 words
The process of claim 14 wherein the pressure of the heated formation is maintained at a higher value than the initial reservoir pressure and the temperature is maintained at the corresponding saturated steam temperature.
Claim 17
Dependent Claim
30 words
The process of claim 15 wherein the pressure of said permeable zone is gradually reduced to about 100 to 200 pounds per square inch over about 2 to 5 years.
Claim 18
Dependent Claim
21 words
The process of claim 1 wherein a non-condensable gas is injected into the permeable zone along with the hot aqueous fluid.
Claim 19
Dependent Claim
11 words
The process of claim 17 wherein the non-condensable gas is air.
Claim 20
Dependent Claim
19 words
The process of claim 6, wherein a non-condensable gas is injected into the permeable zone along with said steam.
Claim 21
Dependent Claim
11 words
The process of claim 19, wherein the non-condensable gas is air.
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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) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |