Electric power supply for use downhole

Claim 2

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; a fluid supply valve means between said source zone and said discharge zone for controlling flow of fluid from said source zone through said engine means; and electrical power generating means for converting said rotational mechanical output of said engine means into electrical output.

Claim 3

The apparatus of claim 1, wherein: said generating means is further characterized as a means for generating an alternating current electrical output; and said apparatus further includes a processing means for processing said alternating current electrical output to provide a smoothed direct current electrical output.

Claim 4

The apparatus of claim 2, wherein said processing means comprises: a rectifier mean for receiving said alternating current electrical output from said generating mean and for providing a varying direct current electrical output; a filter means for receiving said varying direct current electrical output from said rectifier means and for producing a smoothed direct current electrical output; and a regulator means for receiving said smoothed direct current electrical output from said filter means and for producing a constant voltage direct current electrical output.

Claim 5

The apparatus of claim 3, further comprising: means and said regulator means, for receiving and storing said smoothed direct current electrical output from said filter means and for providing electrical output to said regulator means.

Claim 6

The apparatus of claim 4, further comprising: valve control system means for controlling said fluid supply valve means in response to a sensed output from said power storage means.

Claim 7

The apparatus of claim 5, wherein: said valve control system means includes a microprocessor.

Claim 8

The apparatus of claim 1, further comprising: a power storage means for storing said electrical output.

Claim 9

The apparatus of claim 7, further comprising: valve control system means for controlling said fluid supply valve means in response to a sensed output from said power storage means.

Claim 10

The apparatus of claim 8, wherein: said valve control system means includes a microprocessor.

Claim 11

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; and wherein said discharge zone is a substantially atmospheric dump chamber defined entirely in said apparatus.

Claim 12

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; and wherein said discharge zone is a substantially atmospheric dump chamber defined entirely in said apparatus.

Claim 13

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; wherein said high fluid pressure source zone is an enclosed container filled with compressed nitrogen gas; and wherein said fluid powered engine means is a gas turbine driven by said compressed nitrogen gas from said source zone and venting spent nitrogen gas to said discharge zone.

Claim 14

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; wherein said high fluid pressure source zone is an enclosed container filled with compressed nitrogen gas; and wherein said fluid powered engine means is a gas turbine driven by said compressed nitrogen gas from said source zone and venting spent nitrogen gas to said discharge zone.

Claim 15

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; wherein said high fluid pressure source includes an isolation chamber having an isolation piston slidably disposed therein separating said isolation chamber into a well side chamber portion and a tool side chamber portion, said well side chamber portion being in fluid flow communication with a well annulus surrounding said apparatus, said tool side chamber portion being filled with a clean hydraulic fluid; and wherein said fluid powered engine is powered by said clean hydraulic fluid flowing from said tool side chamber portion of said isolation chamber through said engine.

Claim 16

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; wherein said high fluid pressure source includes an isolation chamber having an isolation piston slidably disposed therein separating said isolation chamber into a well side chamber portion and a tool side chamber portion, said well side chamber portion being in fluid flow communication with a well annulus surrounding said apparatus, said tool side chamber portion being filled with a clean hydraulic fluid; and wherein said fluid powered engine is powered by said clean hydraulic fluid flowing from said tool side chamber portion of said isolation chamber through said engine.

Claim 17

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; wherein said high fluid pressure source includes a supply chamber having a pressure transfer piston slidably disposed therein dividing said supply chamber into first and second portions, said first portion being filled with a clean hydraulic fluid and being in fluid flow communication with said engine means, and said second portion being filled with a compressed gas so that said high pressure of said source zone is equal to the pressure of said compressed gas; and wherein said low pressure discharge zone includes an isolation chamber having an isolation piston slidably disposed therein separating said isolation chamber into first and second portions, said first portion being filled with a clean hydraulic fluid and being in fluid flow communication with said engine means, and said second portion being in fluid flow communication with a well annulus surrounding said apparatus so that the low pressure of said discharge zone is equal to hydrostatic pressure in said well annulus.

Claim 18

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; wherein said high fluid pressure source includes a supply chamber having a pressure transfer piston slidably disposed therein dividing said supply chamber into first and second portions, said first portion being filled with a clean hydraulic fluid and being in fluid flow communication with said engine means, and said second portion being filled with a compressed gas so that said high pressure of said source zone is equal to the pressure of said compressed gas; and wherein said low pressure discharge zone includes an isolation chamber having an isolation piston slidably disposed therein separating said isolation chamber into first and second portions, said first portion being filled with a clean hydraulic fluid and being in fluid flow communication with said engine means, and said second portion being in fluid flow communication with a well annulus surrounding said apparatus so that the low pressure of said discharge zone is equal to hydrostatic pressure in said well annulus.

Claim 19

The apparatus of claim 13, further comprising: bypass conduit means for bypassing said engine means and directly communicating said first portions of said supply chamber and said isolation chamber with each other; and one-way check valve means, disposed in said bypass conduit means, for permitting flow of hydraulic fluid from said first portion of said isolation chamber through said bypass conduit means to said first portion of said supply chamber to recompress said compressed gas when annulus pressure in said well annulus is increased to a level greater than the pressure of said compressed gas.

Claim 20

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; first and second isolation chambers; a first isolation piston slidably disposed in said first isolation chamber and dividing said first isolation chamber into a first tool side chamber portion and a first well side chamber portion; a second isolation piston slidably disposed in said second isolation chamber and dividing said second isolation chamber into a second tool side chamber portion and a second well side chamber portion; conduit means for communicating said first and second tool side chamber portions with said fluid powered engine means; and reversing valve means having a first position for communicating a high pressure zone of said well with said first well side chamber portion while simultaneously communicating a low pressure zone of said well with said second well side chamber portion, and having a second position for communicating said high pressure zone with said second well side chamber portion while simultaneously communicating said low pressure zone with said first well side chamber portion, so that said first and second isolation chambers alternatingly define said source zone and said discharge zone.

Claim 21

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; first and second isolation chambers; a first isolation piston slidably disposed in said first isolation chamber and dividing said first isolation chamber into a first tool side chamber portion and a first well side chamber portion; a second isolation piston slidably disposed in said second isolation chamber and dividing said second isolation chamber into a second tool side chamber portion and a second well side chamber portion; conduit means for communicating said first and second tool side chamber portions with said fluid powered engine means; and reversing valve means having a first position for communicating a high pressure zone of said well with said first well side chamber portion while simultaneously communicating a low pressure zone of said well with said second well side chamber portion, and having a second position for communicating said high pressure zone with said second well side chamber portion while simultaneously communicating said low pressure zone with said first well side chamber portion, so that said first and second isolation chambers alternatingly define said source zone and said discharge zone.

Claim 22

The apparatus of claim 15, further comprising: pressure supply control means, operably associated with said reversing valve means, for switching said reversing valve means alternately between its said first and second positions so that fluid pressure from said high pressure zone of said well is substantially continuously communicated to said fluid powered engine means.

Claim 23

The apparatus of claim 16, wherein: said reversing valve means is an electric solenoid operated reversing valve means; and said pressure supply control means is a means for controlling said electric solenoid of said reversing valve means.

Claim 24

The apparatus of claim 15, further comprising: said fluid powered engine means having a high pressure inlet and a low pressure outlet; high pressure shuttle check valve means, disposed in said conduit means, for communicating the one of said isolation chambers which is communicated with said high pressure zone with said high pressure inlet of said fluid powered engine means; and low pressure shuttle check valve means disposed in said conduit means for communicating the other of said isolation chambers with said low pressure outlet of said fluid powered engine means.

Claim 25

The apparatus of claim 15, further comprising: a differential pressure actuating piston means, operably associated with said reversing valve means, for moving said reversing valve means between its said first and second positions; and a pilot valve means for selectively applying a fluid pressure differential across said differential pressure actuating piston means.

Claim 26

The apparatus of claim 19, further comprising: pressure differential supply means for providing fluid pressure communication between said pilot valve means and each of said first and second isolation chambers, so that said fluid pressure differential is the differential between said high and low pressure zones.

Claim 27

The apparatus of claim 20, further comprising: time delay means for delaying communication to said pilot valve means of pressure changes in said first and second isolation chambers; and fluid pressure accumulator means for maintaining a pressure between said pilot valve means and said time delay means, after said reversing valve means begins changing position for a sufficient time to complete a stroke of said differential pressure actuating piston means.

Claim 28

The apparatus of claim 20, further comprising: said pilot valve means having a fixed high pressure inlet from said pressure differential supply means and a fixed low pressure outlet to said pressure differential supply means; high pressure shuttle check valve means, disposed in said pressure differential supply means, for communicating said fixed high pressure inlet with the one of said isolation chambers which is communicated with said high pressure zone; and low pressure shuttle check valve means, disposed in said pressure differential supply means, for communicating said fixed low pressure outlet with the other of said isolation chambers.

Claim 29

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; wherein said high fluid pressure source means is in fluid pressure communication with a well annulus surrounding said apparatus; and wherein said low pressure discharge zone is in fluid pressure communication with tubing pressure in a tubing string by which said apparatus is suspended in a well.

Claim 30

A downhole electrical power supply apparatus, comprising: a high fluid pressure source zone defined at least partially in said apparatus; a low fluid pressure discharge zone defined at least partially in said apparatus; a fluid powered engine means, for providing a rotational mechanical output powered by fluid flowing from said source zone through said engine means to said discharge zone; electrical power generating means for converting said rotational mechanical output of said engine means into electrical output; wherein said high fluid pressure source means is in fluid pressure communication with a well annulus surrounding said apparatus; and wherein said low pressure discharge zone is in fluid pressure communication with tubing pressure in a tubing string by which said apparatus is suspended in a well.

Claim 33

The method of claim 24, wherein: said step (c) is further characterized as generating an alternating current electrical output; and said method further comprises a step of processing said alternating current electrical output to provide a smoothed direct current electrical output.

Claim 34

The method of claim 25, wherein said processing step comprises: rectifying said alternating current electrical output from said generator and providing a varying direct current electrical output; filtering said varying direct current electrical output and producing a smoothed direct current electrical output; and regulating said smoothed direct current electrical output and producing a constant voltage direct current electrical output

Claim 35

The method of claim 26, further comprising: storing said smoothed direct current electrical output in a storage device.

Claim 36

The method of claim 27, further comprising: controlling flow of said power fluid to said engine in response to a sensed output from said storage device.

Claim 39

The method of claim 29, further comprising: isolating said fluid powered engine from contact with said well fluid flowing through said system.