Oil well and method for production of oil through permafrost zone

Claim 2

A well as defined in claim 2 wherein said liquid heat exchange fluid is brine, inhibited aqueous ethylene glycol solution or methanol-water.

Claim 3

A well as defined in claim 1 wherein said means for inhibiting heat transfer is a refrigerant liquid. %. A well as defined in claim 4 wherein said refrigerant liquid is propane, ammonia or a nonflammable liquid-fluorinated hydrocarbon.

Claim 4

A well as defined in claim 1 wherein said inner casing is in a spaced relationship which defines with said pipe an inner annulus.

Claim 5

A well as defined in claim 6 wherein said inner annulus is provided with closure means at a location below the permafrost zone to provide an upper insulation chamber in said annulus.

Claim 6

A well as defined in claim 7 including means in said upper insulation chamber for inhibiting heat transfer from the interior of the pipe to the wall of the inner casing.

Claim 7

A well as defined in claim 8 wherein said means in the upper insulation chamber for inhibiting heat transfer is solid thermal insulation of low conductivity.

Claim 8

A well as defined in claim 7 wherein the annulus between the outer and inner casings contains a liquid heat exchange fluid or a refrigerant liquid.

Claim 9

A well as defined in claim 10 wherein the upper insulation chamber in the inner annulus between the inner casing and the pipe contains thermal insulation of low conductivity.

Claim 10

A process for completing a well for extracting oil from ground containing a permafrost zone which comprises the steps of: a. drilling a first hole from the surface of the ground downwardly at least through the permafrost zone; b. putting an outer casing down into said first hole; c. drilling a second hole smaller in diameter than said first hole from the bottom of said first hole downwardly into the ground to a medial point between the oil level and the bottom of said first hole; d. putting an inner casing down into said second hole to line said second hole, the outer surface of said inner casing and the inner surface of said Outer casing defining an annulus; , e. drilling a third hole smaller in diameter than said second hole downwardly from the bottom of said second hole through the ground into the oil reservoir; f. putting a pipe down through said third hole into said oil reservoir, which pipe extends upwardly to the surface of the ground; and g. introducing into said annulus liquid means for inhibiting heat transfer from the interior of said pipe to the earth surrounding said outer casing.

Claim 11

A process as defined in claim 12 wherein said means for inhibiting heat transfer is a liquid heat exchange fluid.

Claim 12

A process as defined in claim 13 wherein said liquid heat exchange fluid is brine, inhibited aqueous ethylene glycol solution or methanol-water.

Claim 13

A process as defined in claim 12 wherein said means for inhibiting heat transfer is refrigerant liquid.

Claim 14

A process as defined in claim 15 wherein said refrigerant liquid is propane, ammonia or a nonflammable 21 liquid-fluorinated hydrocarbon.

Claim 15

A process as defined in claim 12 wherein the outer surface of the pipe and the inner surface of the inner casing define an inner annulus.

Claim 16

A process as DEFINED in claim 17 including providing said inner annulus with closure means at a strategic location to provide an upper insulation chamber in said inner annulus.

Claim 17

A process as defined in claim 18 including introducing into said upper insulation chamber means for inhibiting heat transfer from the interior of THE pipe to the wall of the inner casing.

Claim 18

A process PROCESS as defined in claim 19 wherein said means in the upper insulation chamber for inhibiting heat transfer is a thermal insulation that has a low conductivity.

Claim 19

A process as defined in claim 20 wherein said thermal insulation is expanded polyurethane, expanded polystyrene or vermiculite.

Claim 20

A process as defined in claim 18 wherein the means for inhibiting heat transfer introduced into the annulus between the outer and inner casings is a liquid heat transfer fluid or a refrigerant liquid.

Claim 21

A process as defined in claim 22 wherein the means for inhibiting heat transfer introduced into the upper insulation chamber in the inner annulus between the inner casing and the pipe is a thermal insulation of low conductivity.

Claim 22

A well for extracting oil from ground containing a permafrost zone comprising: a. a pipe extending downwardly from the surface of the ground to the body of oil; b. an inner casing surrounding the pipe and extending downwardly from the surface of the ground and terminating at a medial point along said pipe below the permafrost zone; c. an outer casing surrounding the inner casing in spaced relationship to define with said inner casing an annulus extending downwardly from the surface of the ground to below the permafrost zone; d. liquid means in the annulus for inhibiting heat transfer from the interior of the pipe to the ground surrounding the outer casing, e. wherein said inner casing is in a spaced relationship which defines with said pipe an inner annulus; f. said inner annulus being provided with closure means at a location below the permafrost zone to provide an upper insulation chamber in said annulus; and g. said upper insulation chamber contains solid thermal insulation selected from expanded polyurethane, expanded polystyrene or vermiculite.