Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
272 words
A method for recovering viscous petroleum from a subterranean, viscous petroleum-containing formation comprising: (a) penetrating the formation with at least two spaced apart wells, one of which is completed as an injection well and one of which is completed as a production well, both wells being completed near the bottom of the formation; (b) injecting a first thermal oil recovery fluid into the injection well and recovering petroleum from the formation via the production well to form a first depleted zone in the formation, until breakthrough of the first thermal recovery fluid at the production well; (c) thereafter converting the production well from the first phase to an injection well and penetrating the formation with at least one first additional production well completed near the top of the formation in a portion of the formation outside the first depleted zone; (d) injecting a second thermal oil recovery fluid into the original injection well and the converted injection well and taking production of petroleum from the formation via the first additional production well until breakthrough of the second thermal recovery fluid at the production well; (e) penetrating the formation with at least one second additional production well located between the original injection well and original production well of the first phase of step (b) and completed near the top of the formation; (f) converting the first additional production well of (c) to an injection well; and (g) injecting a third thermal oil recovery fluid into all of the injection wells and producing petroleum from the second additional production well until breakthrough of the thermal oil recovery fluid at the second additional producing well.
Claim 2
Independent Claim
272 words
A method for recovering viscous petroleum from a subterranean, viscous petroleum-containing formation comprising: (a) penetrating the formation with at least two spaced apart wells, one of which is completed as an injection well and one of which is completed as a production well, both wells being completed near the bottom of the formation; (b) injecting a first thermal oil recovery fluid into the injection well and recovering petroleum from the formation via the production well to form a first depleted zone in the formation, until breakthrough of the first thermal recovery fluid at the production well; (c) thereafter converting the production well from the first phase to an injection well and penetrating the formation with at least one first additional production well completed near the top of the formation in a portion of the formation outside the first depleted zone; (d) injecting a second thermal oil recovery fluid into the original injection well and the converted injection well and taking production of petroleum from the formation via the first additional production well until breakthrough of the second thermal recovery fluid at the production well; (e) penetrating the formation with at least one second additional production well located between the original injection well and original production well of the first phase of step (b) and completed near the top of the formation; (f) converting the first additional production well of (c) to an injection well; and (g) injecting a third thermal oil recovery fluid into all of the injection wells and producing petroleum from the second additional production well until breakthrough of the thermal oil recovery fluid at the second additional producing well.
Claim 3
Dependent Claim
43 words
A method as recited in claim 1 wherein the first thermal oil recovery fluid is a mixture of air and steam and the ratio of from about 0.150 to about 0.650 thousand standard cubic feet of air per barrel of steam (as water).
Claim 4
Dependent Claim
29 words
A method as recited in claim 1 wherein the second thermal oil recovery fluid is selected from the group consisting of air, oxygen enriched air, and substantially pure oxygen.
Claim 5
Dependent Claim
41 words
A method as recited in claim 1 wherein at least two new production wells are completed in step (c), the two wells being on opposite sides of the portion of the formation depleted by injecting the first thermal oil recovery fluid.
Claim 6
Dependent Claim
35 words
A method as recited in claim 4 wherein the two new production wells are located on a line which passes through the midpoint of a line between the original injection well and original production well.
Claim 7
Dependent Claim
24 words
A method as recited in claim 5 wherein the new production wells are located equidistant between the original injection well and original production well.
Claim 8
Dependent Claim
28 words
A method as recited in claim 1 wherein the third thermal oil recovery fluid is selected from the group consisting of air, oxygen-enriched air, and substantially pure oxygen.
Claim 9
Dependent Claim
16 words
A method as recited in claim 1 wherein the first thermal oil recovery fluid is steam.
Claim 10
Dependent Claim
16 words
A method as recited in claim 1 wherein the second thermal oil recovery fluid is steam.
Claim 11
Dependent Claim
16 words
A method as recited in claim 1 wherein the third thermal oil recovery fluid is steam.
Claim 12
Dependent Claim
41 words
A method as recited in claim 1 wherein the first thermal oil recovery fluid is a mixture of steam and from 2.0 to 20.0 percent of a C 3 to C 12 light hydrocarbon, kerosene, naphtha, natural gasoline and mixtures thereof.
Claim 13
Dependent Claim
41 words
A method as recited in claim 1 wherein the second thermal oil recovery fluid is a mixture of steam and from 2.0 to 20.0 percent of a C 3 to C 12 light hydrocarbon, kerosene, naphtha, natural gasoline and mixtures thereof.
Claim 14
Dependent Claim
40 words
A method as recited in claim 1 wherein the third thermal oil recovery fluid is a mixture of steam and from 2.0 to 20.0 percent of C 3 to C 12 light hydrocarbon, kerosene, naphtha, natural gasoline and mixtures thereof.