Hydrocarbon resource recovery system and RF antenna assembly with latching inner conductor and related methods

Patent metadata

Field	Value
Publication number	US-10577905-B2
Application number	US-201815893882-A
Country	US
Kind code	B2
Filing date	Feb 12, 2018
Priority date	Feb 12, 2018
Publication date	Mar 3, 2020
Grant date	Mar 3, 2020

Abstract

A hydrocarbon resource recovery system may include an RF source, and an RF antenna assembly coupled to the RF source and within a wellbore in a subterranean formation for hydrocarbon resource recovery. The RF antenna assembly may include first and second tubular conductors, a dielectric isolator coupled between the first and second tubular conductors, an RF transmission line having an inner conductor and an outer conductor extending within the first tubular conductor, the outer conductor being coupled to the first tubular conductor, and a feed structure coupled to the second tubular conductor. The inner conductor may have a distal end being slidable within the outer conductor and cooperating with the feed structure to define a latching arrangement having a latching threshold lower than an unlatching threshold.

First claim

That which is claimed is:

1. A hydrocarbon resource recovery system comprising:
a radio frequency (RF) source; and
an RF antenna assembly coupled to said RF source and within a wellbore in a subterranean formation for hydrocarbon resource recovery, the RF antenna assembly comprising
first and second tubular conductors,
a dielectric isolator coupled between said first and second tubular conductors,
an RF transmission line comprising an inner conductor and an outer conductor extending within said first tubular conductor, said outer conductor being coupled to said first tubular conductor, and
a feed structure coupled to said second tubular conductor,
said inner conductor having a distal end being slidable within said outer conductor and cooperating with said feed structure to define a latching arrangement having a latching threshold lower than an unlatching threshold.

2. The hydrocarbon resource recovery system of claim 1 wherein the distal end of said inner conductor comprises a plug body having a tapered front end and a radial recess spaced therefrom.

3. The hydrocarbon resource recovery system of claim 2 wherein the tapered front end has a slope being more shallow than a slope of the radial recess.

4. The hydrocarbon resource recovery system of claim 2 wherein said plug body has a fluid passageway extending therethrough.

5. The hydrocarbon resource recovery system of claim 2 wherein said feed structure comprises:
a receptacle body configured to receive said plug body; and
a plurality of biased roller members carried by said receptacle body and configured to sequentially engage the tapered front end and the radial recess of said plug body.

6. The hydrocarbon resource recovery system of claim 5 wherein each biased roller member comprises:
a roller; and
an arm having a proximal end pivotally coupled to said receptacle body and a distal end carrying said roller.

7. The hydrocarbon resource recovery system of claim 5 wherein said receptacle body is slidably moveable within said second tubular conductor.

8. The hydrocarbon resource recovery system of claim 1 wherein said feed structure comprises a forward stop configured to limit forward travel of the distal end of said inner conductor.

9. The hydrocarbon resource recovery system of claim 1 wherein said RF transmission line comprises a plurality of dielectric stabilizers supporting said inner conductor within said outer conductor.

10. A radio frequency (RF) antenna assembly for a hydrocarbon resource recovery system and being positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery, the RF antenna assembly comprising:
first and second tubular conductors;
a dielectric isolator coupled between said first and second tubular conductors;
an RF transmission line comprising an inner conductor and an outer conductor extending within said first tubular conductor, said outer conductor being coupled to said first tubular conductor; and
a feed structure coupled to said second tubular conductor;
said inner conductor having a distal end being slidable within said outer conductor and cooperating with said feed structure to define a latching arrangement having a latching threshold lower than an unlatching threshold.

11. The RF antenna assembly of claim 10 wherein the distal end of said inner conductor comprises a plug body having a tapered front end and a radial recess spaced therefrom.

12. The RF antenna assembly of claim 11 wherein the tapered front end has a slope being more shallow than a slope of the radial recess.

13. The RF antenna assembly of claim 11 wherein said plug body has a fluid passageway extending therethrough.

14. The RF antenna assembly of claim 11 wherein said feed structure comprises:
a receptacle body configured to receive said plug body; and
a plurality of biased roller members carried by said receptacle body and configured to sequentially engage the tapered front end and the radial recess of said plug body.

15. The RF antenna assembly of claim 14 wherein each biased roller member comprises:
a roller; and
an arm having a proximal end pivotally coupled to said receptacle body and a distal end carrying said roller.

16. The RF antenna assembly of claim 14 wherein said receptacle body is slidably moveable within said second tubular conductor.

17. The RF antenna assembly of claim 10 wherein said feed structure comprises a forward stop configured to limit forward travel of the distal end of said inner conductor.

18. A method for hydrocarbon resource recovery from a subterranean formation comprising:
positioning first and second tubular conductors in a wellbore in the subterranean formation with a dielectric isolator coupled between the first and second tubular conductors;
positioning an outer conductor of a radio frequency (RF) transmission line within the first tubular conductor and being coupled to the first tubular conductor; and
positioning an inner conductor of the RF transmission line within the outer conductor and cooperating with a feed structure coupled to the second tubular conductor to define a latching arrangement having a latching threshold lower than an unlatching threshold.

19. The method of claim 18 wherein a distal end of the inner conductor comprises a plug body having a tapered front end and a radial recess spaced therefrom.

20. The method of claim 19 wherein the tapered front end has a slope being more shallow than a slope of the radial recess.

21. The method of claim 19 wherein the plug body has a fluid passageway extending therethrough.

22. The method of claim 19 wherein the feed structure comprises:
a receptacle body configured to receive the plug body; and
a plurality of biased roller members carried by the receptacle body and configured to sequentially engage the tapered front end and the radial recess of the plug body.

23. The method of claim 18 further comprising supplying RF power to the RF transmission line.

Assignees

• Eagle Tech Llc

Inventors

• Wright Brian N
• Hewit Raymond C

Classifications

• E21B43/16

  Enhanced recovery methods for obtaining hydrocarbons · CPC title

• E21B43/2401 Primary

  by means of electricity · CPC title

• H05B6/80

  Apparatus for specific applications (stoves or ranges F24C7/02) · CPC title

• H05B6/52

  Feed lines · CPC title

• H05B2214/03

  Heating of hydrocarbons · CPC title