Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
318 words
A method of recovering viscous petroleum from a subterranean, permeable, viscous petroleum-containing formation, comprising: (a) providing an injection well containing a flow path in fluid communication with at least a portion of the petroleum formation; (b) providing a production well containing at least two separate flow paths, the first path establishing communication between the surface of the earth and the upper half or less of the petroleum formation and the second establishing fluid communication between the surface of the earth and the lower half or less of the petroleum formation, said injection and production well defining a recovery zone within the formation; (c) providing an infill well in fluid communication with the bottom half or less of the formation, said infill well being within the recovery zone defined by the injection well and production well; (d) injecting a thermal oil recovery fluid comprising steam into the injection well and recovering a fluid comprising water and petroleum from the formation via the production well until the fluid being recovered from the production well comprises a predetermined amount of steam or water; (e) thereafter continuing injecting a fluid into the injection well and recovering fluids including petroleum from the formation by the infill well until the fluid being recovered comprises a predetermined fraction of steam and water; (f) injecting a fluid whose mobility is less than steam into the upper portion of the formation adjacent to the production well by means of the first flow path therein in an amount sufficient to reduce permeability of at least a portion of the treated zone; (g) injecting a thermal oil recovery fluid into the infill well and continuing injecting fluid into the injection well, and recovering fluids from the bottom of the formation adjacent the production well by means of the second flow path of the production well until a percentage of water in the fluid being recovered reaches a predetermined value.
Claim 2
Independent Claim
318 words
A method of recovering viscous petroleum from a subterranean, permeable, viscous petroleum-containing formation, comprising: (a) providing an injection well containing a flow path in fluid communication with at least a portion of the petroleum formation; (b) providing a production well containing at least two separate flow paths, the first path establishing communication between the surface of the earth and the upper half or less of the petroleum formation and the second establishing fluid communication between the surface of the earth and the lower half or less of the petroleum formation, said injection and production well defining a recovery zone within the formation; (c) providing an infill well in fluid communication with the bottom half or less of the formation, said infill well being within the recovery zone defined by the injection well and production well; (d) injecting a thermal oil recovery fluid comprising steam into the injection well and recovering a fluid comprising water and petroleum from the formation via the production well until the fluid being recovered from the production well comprises a predetermined amount of steam or water; (e) thereafter continuing injecting a fluid into the injection well and recovering fluids including petroleum from the formation by the infill well until the fluid being recovered comprises a predetermined fraction of steam and water; (f) injecting a fluid whose mobility is less than steam into the upper portion of the formation adjacent to the production well by means of the first flow path therein in an amount sufficient to reduce permeability of at least a portion of the treated zone; (g) injecting a thermal oil recovery fluid into the infill well and continuing injecting fluid into the injection well, and recovering fluids from the bottom of the formation adjacent the production well by means of the second flow path of the production well until a percentage of water in the fluid being recovered reaches a predetermined value.
Claim 3
Dependent Claim
116 words
A method as recited in claim 1 wherein the infill well contains at least two flow paths, a first flow path in fluid communication with the upper half or less of the formation adjacent to the infill well and a second flow path in fluid communication with the bottom half or less of the portion of the formation adjacent to the infill well said second flow path being used for fluid production in step (e) and fluid injection in step (g), and comprising the additional step of injecting a low mobility fluid into the upper portion of the formation adjacent to the infill well by use of the first flow path between steps (d) and (g).
Claim 4
Dependent Claim
112 words
A method as recited in claim 1 wherein the injection well contains at least two flow paths, a first flow path in fluid communication with the upper half or less of the formation adjacent to the injection well and a second flow path in fluid communication with the bottom half or less of the portion of the formation adjacent to the injection well, said second flow path being used for fluid injection in steps (d) and (e) and comprising the additional step of injecting a low mobility fluid into the upper portion of the formation adjacent to the injection well by means of the first flow path between steps (d) and (g).
Claim 5
Dependent Claim
42 words
A method as recited in claim 1 wherein the low mobility fluid injected into the upper portion of the formation adjacent to the production well in step (f) is substantially all liquid phase water whose temperature is from 40° to 200° F.
Claim 6
Dependent Claim
40 words
A method as recited in claim 1 wherein the low mobility fluid injected into the upper portion of the formation in step (f) comprises water containing from 100 to 10,000 parts per million of a hydrophilic polymeric viscosity increasing substance.
Claim 7
Dependent Claim
13 words
A method as recited in claim 5 wherein the hydrophilic polymer is polyacrylamide.
Claim 8
Dependent Claim
13 words
A method as recited in claim 5 wherein the hydrophilic polymer is polysaccharide.
Claim 9
Dependent Claim
33 words
A method as recited in claim 1 wherein the low mobility fluid injected into the formation in step (f) comprises an aqueous solution containing from 100 to 5,000 parts per million colloidal silica.
Claim 10
Dependent Claim
31 words
A method as recited in claim 1 wherein the low mobility fluid injected into the upper portion of the formation in step (f) comprises an aqueous fluid containing an emulsifying surfactant.
Claim 11
Dependent Claim
21 words
A method as recited in claim 9 wherein the surfactant is petroleum sulfonate whose equivalent weight is from 325 to 475.
Claim 12
Dependent Claim
35 words
A method as recited in claim 1 wherein the low mobility fluid injected into the upper part of the formation in step (f) is an emulsion whose oil content is from 1 to 40 percent.
Claim 13
Dependent Claim
28 words
A method as recited in claim 11 wherein the oil content of the emulsion is selected to maintain the viscosity at a value from 1 to 50 centipoise.
Claim 14
Dependent Claim
39 words
A method as recited in claim 1 wherein the low mobility fluid of step (f) is water containing an emulsifying surfactant which forms an emulsion in the zone of the formation into which it is injected with residual oil.
Claim 15
Independent Claim
305 words
A method of recovering viscous petroleum from a subterranean, permeable, viscous petroleum-containing formation, comprising: (a) providing an injection well containing a flow path in fluid communication with at least a portion of the bottom of the petroleum formation; (b) providing a production well in fluid communication with at least a portion of the petroleum formation; (c) providing an infill well containing a first flow path in fluid communication with the top half or less of the formation, and a second flow path in fluid communication with the bottom half or less of the formation, said infill well being within the recovery zone defined by the injection well and production well; (d) injecting a thermal oil recovery fluid comprising steam into the injection well and recovering fluid including petroleum from the formation via the production well until the fluid being recovered from the production well comprises a predetermined amount of steam and water; (e) thereafter continuing injecting steam into the injection well and recovering fluids including petroleum from the bottom of the formation by the second flow path of the infill well until the fluid being recovered comprises a predetermined fraction of steam and water; (f) injecting a fluid having lower mobility than steam into the upper portion of the formation adjacent to the infill well by means of the first flow path therein in an amount sufficient to reduce the flow rate of steam through at least a portion of the treated zone, after completion of step (d); (g) injecting a thermal oil recovery fluid into the second flow path of the infill well while continuing injecting fluid into the injection well and recovering fluids from the bottom of the formation adjacent the production well by means of the production well until a percentage of water in the fluid being recovered reaches a predetermined value.
Claim 16
Independent Claim
305 words
A method of recovering viscous petroleum from a subterranean, permeable, viscous petroleum-containing formation, comprising: (a) providing an injection well containing a flow path in fluid communication with at least a portion of the bottom of the petroleum formation; (b) providing a production well in fluid communication with at least a portion of the petroleum formation; (c) providing an infill well containing a first flow path in fluid communication with the top half or less of the formation, and a second flow path in fluid communication with the bottom half or less of the formation, said infill well being within the recovery zone defined by the injection well and production well; (d) injecting a thermal oil recovery fluid comprising steam into the injection well and recovering fluid including petroleum from the formation via the production well until the fluid being recovered from the production well comprises a predetermined amount of steam and water; (e) thereafter continuing injecting steam into the injection well and recovering fluids including petroleum from the bottom of the formation by the second flow path of the infill well until the fluid being recovered comprises a predetermined fraction of steam and water; (f) injecting a fluid having lower mobility than steam into the upper portion of the formation adjacent to the infill well by means of the first flow path therein in an amount sufficient to reduce the flow rate of steam through at least a portion of the treated zone, after completion of step (d); (g) injecting a thermal oil recovery fluid into the second flow path of the infill well while continuing injecting fluid into the injection well and recovering fluids from the bottom of the formation adjacent the production well by means of the production well until a percentage of water in the fluid being recovered reaches a predetermined value.
Claim 17
Dependent Claim
111 words
A method as recited in claim 14 wherein the injection well contains at least two flow paths, a first flow path in fluid communication with the upper half or less of the formation adjacent to the injection well and a second flow path in fluid communication with the bottom half or less of the portion of the formation adjacent to the injection well, said second flow path being used for fluid injection in steps (d), (e) and (g) and comprising the additional step of injecting a low permeability fluid into the upper portion of the formation adjacent to the infill well via the first flow path between steps (d) and (g).
Claim 18
Dependent Claim
42 words
A method as recited in claim 14 wherein the low mobility fluid injected into the upper portion of the formation adjacent to the production well in step (f) is substantially all liquid phase water whose temperature is from 40° to 200° F.
Claim 19
Dependent Claim
40 words
A method as recited in claim 14 wherein the low mobility fluid injected into the upper portion of the formation in step (f) comprises water containing from 100 to 10,000 parts per million of a hydrophilic polymeric viscosity increasing substance.
Claim 20
Dependent Claim
13 words
A method as recited in claim 17 wherein the hydrophilic polymer is polyacrylamide.
Claim 21
Dependent Claim
13 words
A method as recited in claim 17 wherein the hydrophilic polymer is polysaccharide.
Claim 22
Dependent Claim
33 words
A method as recited in claim 14 wherein the low mobility fluid injected into the formation in step (f) comprises an aqueous solution containing from 100 to 5,000 parts per million colloidal silica.
Claim 23
Dependent Claim
31 words
A method as recited in claim 14 wherein the low mobility fluid injected into the upper portion of the formation in step (f) comprises an aqueous fluid containing an emulsifying surfactant.
Claim 24
Dependent Claim
21 words
A method as recited in claim 21 wherein the surfactant is petroleum sulfonate whose equivalent weight is from 325 to 475.
Claim 25
Dependent Claim
22 words
A method as recited in claim 21 wherein the fluid is an emulsion whose oil content is from 1 to 40 percent.
Claim 26
Dependent Claim
28 words
A method as recited in claim 23 wherein the oil content of the emulsion is selected to maintain the viscosity at a value from 1 to 50 centipoise.
Claim 27
Dependent Claim
28 words
A method as recited in claim 21 wherein the fluid is an oil-free aqueous solution which forms an emulsion in the treated zone with residual oil contained therein.
Claim 28
Independent Claim
307 words
A method of recovering viscous petroleum from a subterranean, permeable, viscous petroleum-containing formation, comprising: (a) providing a production well in fluid communication with a substantial amount of vertical thickness of the petroleum formation; (b) providing an injection well containing at least two separate flow paths, one between the surface of the earth and the upper half or less of the petroleum formation and the second being in fluid communication between the surface of the earth and the lower half or less of the petroleum formation, said injection and production well defining a recovery zone within the formation; (c) providing an infill well in fluid communication with the bottom half or less of the formation, said infill well being within the recovery zone defined by the injection well and production well; (d) injecting a thermal oil recovery fluid comprising steam into the injection well via the second flow path and recovering fluid including petroleum from the formation via the production well until the fluid being recovered from the production well comprises a predetermined amount of steam and water; (e) thereafter continuing injecting fluid into the injection well and recovering fluids including petroleum from the formation by the infill well until the fluid being recovered comprises a predetermined fraction of steam and water; (f) injecting a fluid whose mobility is less than steam into the upper portion of the formation adjacent to the injection well by means of the first flow path therein in an amount sufficient to reduce the flow rate of steam through at least a portion of the treated zone; (g) injecting a thermal oil recovery fluid into the infill well and recovering fluids from the bottom of the formation adjacent the production well while continuing injecting fluid into the injection well until a percentage of water in the fluid being recovered reaches a predetermined value.
Claim 29
Independent Claim
307 words
A method of recovering viscous petroleum from a subterranean, permeable, viscous petroleum-containing formation, comprising: (a) providing a production well in fluid communication with a substantial amount of vertical thickness of the petroleum formation; (b) providing an injection well containing at least two separate flow paths, one between the surface of the earth and the upper half or less of the petroleum formation and the second being in fluid communication between the surface of the earth and the lower half or less of the petroleum formation, said injection and production well defining a recovery zone within the formation; (c) providing an infill well in fluid communication with the bottom half or less of the formation, said infill well being within the recovery zone defined by the injection well and production well; (d) injecting a thermal oil recovery fluid comprising steam into the injection well via the second flow path and recovering fluid including petroleum from the formation via the production well until the fluid being recovered from the production well comprises a predetermined amount of steam and water; (e) thereafter continuing injecting fluid into the injection well and recovering fluids including petroleum from the formation by the infill well until the fluid being recovered comprises a predetermined fraction of steam and water; (f) injecting a fluid whose mobility is less than steam into the upper portion of the formation adjacent to the injection well by means of the first flow path therein in an amount sufficient to reduce the flow rate of steam through at least a portion of the treated zone; (g) injecting a thermal oil recovery fluid into the infill well and recovering fluids from the bottom of the formation adjacent the production well while continuing injecting fluid into the injection well until a percentage of water in the fluid being recovered reaches a predetermined value.
Claim 30
Dependent Claim
42 words
A method as recited in claim 26 wherein the low mobility fluid injected into the upper portion of the formation adjacent to the injection well in step (f) is substantially all liquid phase water whose temperature is from 40° to 200° F.
Claim 31
Dependent Claim
40 words
A method as recited in claim 26 wherein the low mobility fluid injected into the upper portion of the formation in step (f) comprises water containing from 100 to 10,000 parts per million of a hydrophilic polymeric viscosity increasing substance.
Claim 32
Dependent Claim
13 words
A method as recited in claim 28 wherein the hydrophilic polymer is polyacrylamide.
Claim 33
Dependent Claim
13 words
A method as recited in claim 28 wherein the hydrophilic polymer is polysaccharide.
Claim 34
Dependent Claim
33 words
A method as recited in claim 26 wherein the low mobility fluid injected into the formation in step (f) comprises an aqueous solution containing from 100 to 5,000 parts per million colloidal silica.
Claim 35
Dependent Claim
31 words
A method as recited in claim 26 wherein the low mobility fluid injected into the upper portion of the formation in step (f) comprises an aqueous fluid containing an emulsifying surfactant.
Claim 36
Dependent Claim
21 words
A method as recited in claim 32 wherein the surfactant is petroleum sulfonate whose equivalent weight is from 325 to 475.
Claim 37
Dependent Claim
22 words
A method as recited in claim 32 wherein the fluid is an emulsion whose oil content is from 1 to 40 percent.
Claim 38
Dependent Claim
28 words
A method as recited in claim 34 wherein the oil content of the emulsion is selected to maintain the viscosity at a value from 1 to 50 centipoise.
Claim 39
Dependent Claim
28 words
A method as recited in claim 32 wherein the fluid is a substantially oil-free solution of surfactant which forms an emulsion in the treated zone with residual oil.