Downhole tool with C-ring closure seat and method

1. A downhole tool including a closure seat for receiving a closure and thereby increasing fluid pressure above the closure seat to perform an operation on the downhole tool and/or another downhole tool, comprising:

a tool body having a central throughbore for passing the closure through the tool body, the closure seat having a radially retracted and inward compressed position when positioned within the tool body for seating with the closure while the central throughbore restricts radial expansion of the closure seat;

a connector for temporarily limiting axial movement of the closure seat with respect to the tool body, and releasing the closure seat to move axially to a radially expanded position within the tool body to release the closure seat from the central throughbore and allow the closure seat to expand to an unbiased position and release the closure; and

a seal body positioned for sealing with the closure; and

an annular seal supported in an annular groove in the seal body above the closure seat for sealing between the closure and the seal body while the closure is seated on the closure seat.

2. The downhole tool as defined in claim 1 , further comprising:

the seal body having an external seal for sealing with the throughbore in the down hole tool.

3. The downhole tool as defined in claim 1 , wherein the connector comprises one or more shear pins.

4. The downhole tool as defined in claim 1 , wherein the tool body includes an actuation port for passing fluid from above the seated closure to operate the tool and/or the another downhole tool.

5. The downhole tool as defined in claim 1 , wherein the closure seat includes a plurality of radially outward extending tabs for engaging a wall of the central throughbore in the tool body when the closure is in its initial position.

6. The downhole tool as defined in claim 1 , wherein the connector releases the closure seat for axial movement relative to the tool body, and a stop limits further downward movement of the released closure seat.

7. The downhole tool as defined in claim 6 , wherein the stop moves radially outward to allow for further downward movement of the closure seat.

8. The downhole tool as defined in claim 6 , wherein the stop limits downward movement of the seated closure when the closure is in the releasing position within the tool body.

9. The downhole tool as defined in claim 1 , further comprising:

one or more safety connectors for limiting axial movement of the closure seat with respect to the tool body after the closure seat has disengaged from its radially retracted position, and thereafter permitting further downward movement of the closure seat to release the closure.

10. The downhole tool as defined in claim 1 , wherein the tool body has a plurality of closure seats which sequentially operate the downhole tool and/or another downhole tool.

11. A downhole tool including a closure seat for receiving a closure and thereby increasing fluid pressure above the closure seat to perform an operation on the downhole tool and/or another downhole tool, comprising:

a tool body having a central throughbore for passing the closure through the tool body, a portion of the central throughbore having a restricted diameter;

a closure seat having a radially retracted position when positioned within the restricted diameter portion of the tool body for seating with the closure while the restricted diameter portion of the central throughbore restricts radial expansion of the closure seat, the closure seat including a plurality of radially outward extending tabs for engaging a wall of the restricted diameter portion of the central throughbore in the tool body when the closure is in its initial position;

a seal body having an external seal for sealing with the throughbore in the down hole tool;

an annular seal supported in an annular groove in the seal body for sealing with the closure while seated on the closure seat; and

a connector for temporarily limiting axial movement of the closure seat with respect to the tool body, and releasing the closure seat to move axially to a radially expanded position for allowing expansion of the closure seat and release the closure.

12. The downhole tool as defined in claim 11 , wherein the tool body includes an actuation port for passing fluid from above the seated closure to operate the tool and/or the another downhole tool.

13. The downhole tool as defined in claim 11 , wherein the seal body includes circumferentially spaced slot seats for receiving a radial projection of the closure seat, such a radially outward surface of each projection engages a wall of the central throughbore to retain the closure seat in the compressed position.

14. The downhole tool as defined in claim 13 , wherein the circumferentially spaced slots in the seal body limit axial movement of a closure seat with respect to the seal body in both an upward direction and a downward direction.

15. A method of operating a downhole tool including a closure seat for receiving a closure and thereby increasing fluid pressure above the closure seat to perform an operation on the downhole tool and/or another downhole tool, comprising:

providing a tool body with a central throughbore for passing the closure through the tool body;

providing a closure seat within the tool body having a radially retracted and inward position for seating with the closure while in a restricting portion of the central throughbore;

providing a seal body for supporting the closure seat, the seal body including circumferentially spaced slots for receiving a radial projection of the closure seat, such a radially outward surface of each projection engages a wall of the central throughbore to retain the closure seat in the compressed position;

temporarily limiting axial movement of the closure seat; and

releasing the closure seat to move axially within the tool body such that the closure seat is in a radially expanded and unbiased position while within a releasing portion of the tool body to allow expansion of the closure seat to release the closure.

16. The method as defined in claim 15 , further comprising:

positioning the seal body above the closure seat; and

providing an annular seal supported on the seal body for sealing between the closure and the seal body while the closure is seated on the closure seat.

17. The method as defined in claim 15 , further comprising:

a seal body having an external seal for sealing with the central throughbore in the downhole tool.

18. The method as defined in claim 15 , wherein the tool body includes an actuation port for passing fluid from above the seated closure to operate the tool and/or the another downhole tool.

19. A downhole tool for performing a downhole operation with a downhole device having a retainer, the downhole tool comprising:

a tool body having a central throughbore for passing a closure through the tool body;

a closure seat having a radially retracted position when positioned within the tool body for seating with the closure while the central throughbore restricts radial expansion of the closure seat;

a seal body having an external seal for sealing with the throughbore in the down hole tool;

a connector initially limiting axial movement of the closure seat with respect to the tool body when held in an initial position by the retainer, and when moved out of engagement with the retainer, releasing the closure seat to move axially with respect to the tool body to a radially expanded position for releasing position when the closure seat moves radially outward to an expanded position and releases the closure; and

the seal body including circumferentially spaced slots each for receiving a radial projection on the closure seat, such that a radially outward surface of each projection engages a wall of the central throughbore to retain the closure seat in the radially retracted position.

20. The downhole tool as defined in claim 19 , wherein the tool body includes an actuation port for passing fluid from above the seated closure to operate the tool and/or the another downhole tool.

21. The downhole tool as defined in claim 19 , wherein the tool body has a plurality of closure seats which sequentially operate the downhole tool and/or another downhole tool.

22. A method of using a downhole tool including a closure seat for receiving a closure and thereby increasing fluid pressure above the closure seat to perform an operation on the downhole tool or another downhole tool having a retainer, the method comprising:

providing a tool body having a central throughbore for passing the closure through the tool body;

initially positioning a radially outward biased closure seat within the tool body in a radially retracted and inward compressed position for seating with the closure while the central throughbore restricts radial expansion of the closure seat;

positioning a seal body for sealing with the closure while on the closure seat;

supporting an annular seal in an annular groove in the seal body above the closure seat for sealing between the closure and the seal body while the closure is seated on the closure seat; and

initially limiting axial movement of the closure seat with respect to the tool body when the closure seat is held in an initial position by the retainer, and when moved out of engagement with the retainer, releasing the closure seat to move axially with respect to the tool body and to a radially expanded position within the tool body in response to its radially outward bias such that the closure seat moves radially outward to the radially expanded position and releases the closure.

23. The method as defined in claim 22 , wherein the tool body includes an actuation port for passing fluid from above the seated closure to operate the tool and/or the another downhole tool.

24. The method as defined in claim 22 , wherein the closure seat includes a plurality of radially outward extending tabs for engaging a wall of the central throughbore in the tool body when the closure is in its initial position.