Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
162 words
A method for processing oil shale in an in situ oil shale retort in a subterranean formation containing oil shale comprising the steps of: excavating a first portion of formation to form at least one void within the boundaries of an in situ oil shale retort site; explosively expanding a second portion of formation within the boundaries of the in situ oil shale retort site towards such a void to form a fragmented permeable mass of formation particles containing oil shale in such an in situ oil shale retort; retorting the particles containing oil shale in the fragmented mass to produce an in situ fragmented permeable mass of particles containing treated oil shale in a spent in situ retort; introducing water containing undissolved impurities into an upper portion of the spent in situ retort; and withdrawing water from a lower portion of the spent retort having a concentration of undissolved impurities lower than the concentration of undissolved impurities in the introduced water.
Claim 2
Independent Claim
162 words
A method for processing oil shale in an in situ oil shale retort in a subterranean formation containing oil shale comprising the steps of: excavating a first portion of formation to form at least one void within the boundaries of an in situ oil shale retort site; explosively expanding a second portion of formation within the boundaries of the in situ oil shale retort site towards such a void to form a fragmented permeable mass of formation particles containing oil shale in such an in situ oil shale retort; retorting the particles containing oil shale in the fragmented mass to produce an in situ fragmented permeable mass of particles containing treated oil shale in a spent in situ retort; introducing water containing undissolved impurities into an upper portion of the spent in situ retort; and withdrawing water from a lower portion of the spent retort having a concentration of undissolved impurities lower than the concentration of undissolved impurities in the introduced water.
Claim 3
Dependent Claim
15 words
A method as claimed in claim 1 in which the introduced water contains hydrocarbon impurities.
Claim 4
Dependent Claim
19 words
A method as claimed in claim 1 in which the introduced water comprises steam generator blowdown containing undissolved solids.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 1 in which the introduced water comprises process water from retorting oil shale.
Claim 6
Independent Claim
163 words
A method for processing oil shale in an in situ oil shale retort in a subterranean formation containing oil shale comprising the steps of: excavating a first portion of formation to form at least one void within the boundaries of an in situ oil shale retort site; explosively expanding a second portion of formation within the boundaries of the in situ oil shale retort site towards such a void to form a fragmented permeable mass of formation particles containing oil shale in such an in situ oil shale retort; retorting the particles containing oil shale in the fragmented mass to produce an in situ fragmented permeable mass of particles containing treated oil shale in a spent in situ retort; introducing water containing dissolved hydrocarbon impurities into an upper portion of the spent retort; and withdrawing water from a lower portion of the spent retort having a concentration of dissolved hydrocarbon impurities lower than the concentration of dissolved hydrocarbon impurities in the introduced water.
Claim 7
Independent Claim
163 words
A method for processing oil shale in an in situ oil shale retort in a subterranean formation containing oil shale comprising the steps of: excavating a first portion of formation to form at least one void within the boundaries of an in situ oil shale retort site; explosively expanding a second portion of formation within the boundaries of the in situ oil shale retort site towards such a void to form a fragmented permeable mass of formation particles containing oil shale in such an in situ oil shale retort; retorting the particles containing oil shale in the fragmented mass to produce an in situ fragmented permeable mass of particles containing treated oil shale in a spent in situ retort; introducing water containing dissolved hydrocarbon impurities into an upper portion of the spent retort; and withdrawing water from a lower portion of the spent retort having a concentration of dissolved hydrocarbon impurities lower than the concentration of dissolved hydrocarbon impurities in the introduced water.
Claim 8
Independent Claim
156 words
A method for processing oil shale in an in situ oil shale retort in a subterranean formation containing oil shale comprising the steps of: excavating a first portion of formation to form at least one void within the boundaries of an in situ oil shale retort site; explosively expanding a second portion of formation within the boundaries of the in situ oil shale retort site towards such a void to form a fragmented permeable mass of formation particles containing oil shale in such an in situ oil shale retort; retorting the particles containing oil shale in the fragmented mass to produce an in situ fragmented permeable mass of particles containing treated oil shale in a spent in situ retort; introducing water into the spent in situ retort, at least a portion of the fragmented mass in the spent retort being at a sufficient temperature to generate steam; and withdrawing steam from the spent in situ retort.
Claim 9
Independent Claim
156 words
A method for processing oil shale in an in situ oil shale retort in a subterranean formation containing oil shale comprising the steps of: excavating a first portion of formation to form at least one void within the boundaries of an in situ oil shale retort site; explosively expanding a second portion of formation within the boundaries of the in situ oil shale retort site towards such a void to form a fragmented permeable mass of formation particles containing oil shale in such an in situ oil shale retort; retorting the particles containing oil shale in the fragmented mass to produce an in situ fragmented permeable mass of particles containing treated oil shale in a spent in situ retort; introducing water into the spent in situ retort, at least a portion of the fragmented mass in the spent retort being at a sufficient temperature to generate steam; and withdrawing steam from the spent in situ retort.
Claim 10
Dependent Claim
31 words
A method as claimed in claim 6 in which the water is introduced at the top of the spent retort and steam is withdrawn from the top of the spent retort.
Claim 11
Dependent Claim
21 words
A method as claimed in claim 6 in which the water contains hydrocarbon impurities and steam containing vaporized hydrocarbons is withdrawn.
Claim 12
Dependent Claim
18 words
A method as claimed in claim 6 in which the water comprises steam generator blowdown containing dissolved solids.
Claim 13
Dependent Claim
18 words
A method as claimed in claim 6 in which the water comprises steam generator blowdown containing undissolved solids.
Claim 14
Dependent Claim
18 words
A method as claimed in claim 6 in which the water comprises process water from retorting oil shale.