Oil production processes and apparatus

Claim 2

An oil recovery string for use in recovering oil from a natural oil-bearing formation with the aid of thermal energy supplied by a fluid-heating medium, said string comprising a tubular heat-conducting casing having oil entry apertures disposed at intervals therealong, an oil-receiving pipe located within said casing and having peripheral openings in sealed communication with said oil-receiving apertures in the casing, and wherein between said casing and said oil-receiving pipe there is a passageway along which heated fluid medium can be circulated in heat-exchange relationship with the casing.

Claim 3

An oil recovery string according to claim 1, wherein the string is formed so that the whole or substantially the whole of the interior surface of said casing is exposed to heated fluid when this is circulated along said passageway.

Claim 4

An oil recovery string according to claim 1, wherein said oil-receiving pipe is disposed so that its axis is substantially centrally located within the cross-section of said casing, wherein there is a tube extending along said string, between said oil-receiving pipe and the casing, and wherein the interior of said tube and the free space which is external to said tube and is between the oil-receiving pipe and the casing constitute reaches of a said passageway along which heated fluid medium can be circulated within the string.

Claim 5

A process for recovery of oil from a natural oil-bearing formation utilising thermal energy supplied by a fluid heating meadium to cause or accelerate flow of oil from the formation into an oil recovery duct, with the improvement that in a direction along the formation there is installed at least one composite heating and oil recovery string having a heat conducting casing within which there is at least one passageway for conducting fluid heating medium along the string in heat exchange relationship with such casing, and within which casing there is also at least one duct for conducting oil along the string, the said casing having peripheral oil entry apertures at intervals therealong (via) which apertures are in sealed communication with (the) said oil-receiving duct located within said casing, (is in communication with the formation,) and fluid heating medium is (circulated) forced along said heating passageway to heat a volume of the oil-bearing formation by heat transfer from the string so that oil is caused to gravitate from the formation into said oil-receiving duct via said oil entry apertures.

Claim 6

A process for recovery of oil from a natural oil-bearing formation utilising thermal energy supplied by a fluid heating meadium to cause or accelerate flow of oil from the formation into an oil recovery duct, with the improvement that in a direction along the formation there is installed at least one composite heating and oil recovery string having a heat conducting casing within which there is at least one passageway for conducting fluid heating medium along the string in heat exchange relationship with such casing, and within which casing there is also at least one duct for conducting oil along the string, the said casing having peripheral oil entry apertures at intervals therealong (via) which apertures are in sealed communication with (the) said oil-receiving duct located within said casing, (is in communication with the formation,) and fluid heating medium is (circulated) forced along said heating passageway to heat a volume of the oil-bearing formation by heat transfer from the string so that oil is caused to gravitate from the formation into said oil-receiving duct via said oil entry apertures.

Claim 7

A process according to claim 4, wherein said string extends along the formation at an inclination so that oil entering said oil-receiving duct flows therealong under gravity.

Claim 8

A process according to claim 4, wherein within said casing there is also a return tube for the fluid heating medium and the fluid heating medium is forced along said passageway in contact with said casing, from one end of said string to the other end thereof, at which other end said fluid heating medium enters said return tube and then flows along that tube back to said one end of the string.

Claim 9

A process according to claim 4, wherein the opposed ends of said casing are connected into a closed circuit along which the fluid heating medium is circulated.

Claim 10

A process for recovery of oil from a natural oil-bearing formation utilizing thermal energy supplied by a fluid heating medium to cause or accelerate flow of oil from the formation into an oil recovery duct, with the improvement that in a direction along the formation there is installed at least one composite heating and oil recovery string comprising a tubular casing having ports at intervals therealong via which the interior of the casing is in communication with the formation, and comprising a plurality of fluid conducting pipes which extend along the interior of said casing and are in communication with ports in different portions of the length of the string, and at intervals of time fluid heating medium is forced along said pipes and into said formation via said ports to heat a volume of the oil-bearing formation so that oil is caused to gravitate from the formation into said oil-receiving duct via said ports.

Claim 11

A process for recovery of oil from a natural oil-bearing formation utilizing thermal energy supplied by a fluid heating medium to cause or accelerate flow of oil from the formation into an oil recovery duct, with the improvement that in a direction along the formation there is installed at least one composite heating and oil recovery string comprising a tubular casing having ports at intervals therealong via which the interior of the casing is in communication with the formation, and comprising a plurality of fluid conducting pipes which extend along the interior of said casing and are in communication with ports in different portions of the length of the string, and at intervals of time fluid heating medium is forced along said pipes and into said formation via said ports to heat a volume of the oil-bearing formation so that oil is caused to gravitate from the formation into said oil-receiving duct via said ports.

Claim 12

An oil recovery string for use in recovering oil from a natural oil-bearing formation with the aid of thermal energy supplied by a fluid heating medium, said string comprising a tubular casing adapted to be laid in a direction along an oil-bearing formation, said casing having ports at intervals therealong via which oil gravitating from regions of the formation above the string can enter said casing, and having partitioning means subdividing the interior of the casing into different compartments distributed along the casing, and a plurality of fluid conducting pipes which extend along the interior of said casing and have fluid discharge ends thereof disposed in different said compartments to permit heating fluid to be intermittently discharged from ports in different portions of the length of the casing, for heating oil in said regions of the formation, by forcing such medium intermittently through said pipes.

Claim 13

An oil recovery string for use in recovering oil from a natural oil-bearing formation with the aid of thermal energy supplied by a fluid heating medium, said string comprising a tubular casing adapted to be laid in a direction along an oil-bearing formation, said casing having ports at intervals therealong via which oil gravitating from regions of the formation above the string can enter said casing, and having partitioning means subdividing the interior of the casing into different compartments distributed along the casing, and a plurality of fluid conducting pipes which extend along the interior of said casing and have fluid discharge ends thereof disposed in different said compartments to permit heating fluid to be intermittently discharged from ports in different portions of the length of the casing, for heating oil in said regions of the formation, by forcing such medium intermittently through said pipes.