Formation tester tool assembly and methods of use

• US 7,260,985 B2
• Filed: 05/20/2005
• Issued: 08/28/2007
• Est. Priority Date: 05/21/2004
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Stone, James E., Sherrill, Kristopher V., McGregor, Malcolm Douglas, Gilbert, Gregory N., Maranuk, Christopher Anthony
• Primary Examiner(s): RAEVIS, ROBERT R
• Application Number:
  US11/133,712
• Publication Number:
  US 20050257630A1
• Time in Patent Office: 830 Days
• Field of Search: 731/522.4
• US Class Current: 73/152.24
• CPC Class Codes: E21B 49/10 using side-wall fluid samplers or testers
• CPC Class Codes: G01N 1/10 in the liquid or fluent state burettes, pipettes B01L3/02; sampling of ground water E02D1/06; metering by volume of fluids or fluent solid material G01F11/00, G01F13/00

Abstract

A downhole, extendable testing apparatus and methods of use are described and claimed herein. In one embodiment, an extendable sample device is connected to a draw down piston assembly. A position indicator may be used to show the position of the draw down piston during movement, and the draw down piston may be stopped and re-started, and moved at different rates. A filter may be used to clean fluids drawn into the extendable sample device. In another embodiment, the extendable sample device may connected to a hydraulic circuit. The hydraulic circuit may include accumulators for accumulating fluid pressures and operating the apparatus. Further apparatus and methods are disclosed herein.

Claims

1. A downhole apparatus comprising:

a drill collar having an outer surface for interaction with an earth formation;

an extendable sample device having a bore and recessed beneath said outer surface in a first position to extend beyond said outer surface to a second position;

a first draw down chamber slidably retaining a first draw down piston, said first draw down piston actuatable between a first position and a second position and said first draw down chamber in fluid communication with said extendable sample device;

a flow line between said extendable sample device and said first draw down chamber, said bore and said flow line to receive at least formation fluid from the earth formation; and

a second draw down chamber slidably retaining a second draw down piston, said second draw down chamber in fluid series with said first draw down chamber and said extendable sample device.

2. The apparatus of claim 1 wherein said first and second draw down chambers have different volumes.

3. The apparatus of claim 1 wherein said first and second draw down pistons are operable independently of each other.

4. A downhole apparatus comprising:

a drill collar having an outer surface for interaction with an earth formation;

an extendable sample device having a bore and recessed beneath said outer surface in a first position to extend beyond said outer surface to a second position;

a draw down chamber slidably retaining a draw down piston, said draw down piston actuatable between a first position and a second position and said draw down chamber in fluid communication with said extendable sample device;

a flow line between said extendable sample device and said draw down chamber, said bore and said flow line to receive at least formation fluid from the earth formation; and

a position indicator in communication with said draw down chamber to signal a position of said draw down piston.

5. The apparatus of claim 4 wherein said position indicator is any one of an acoustic sensor, an optical sensor, a potentiometer, a resistance-measuring device, and a contact switch to signal said draw down piston first position.

6. The apparatus of claim 4 further comprising a controller programmed to command said draw down piston to stop at a third position within said draw down chamber between said first and second positions, and to command said draw down piston to be restarted.

7. The apparatus of claim 6 further comprising:

a solenoid valve;

a shutoff valve; and

wherein said controller communicates with said valves to command said draw down piston.

8. The apparatus of claim 4 further comprising a filter disposed in said flow line.

9. The apparatus of claim 4 further comprising:

a hydraulic circuit in fluid communication with said extendable sample device and said draw down chamber; and

said hydraulic circuit including an accumulator to communicate fluid with at least one of said extendable sample device and said draw down chamber.

10. The apparatus of claim 9 wherein said accumulator is any one of a retract accumulator, an extend accumulator and a draw down accumulator.

11. The apparatus of claim 9 wherein said hydraulic circuit comprises valves to divert fluid from a retract side of said extendable sample device toward an extend side of said extendable sample device as said extendable sample device is actuated from said first position to said second position.

12. The apparatus of claim 4 further comprising:

a hydraulic circuit having a fluid pressure; and

a hydraulic reservoir accumulator, said hydraulic reservoir accumulator in fluid communication with an annulus surrounding said drill collar and said hydraulic circuit such that said reservoir accumulator communicates an annulus fluid pressure to said hydraulic circuit.

13. The apparatus of claim 12 wherein said hydraulic reservoir accumulator further comprises:

a body having an internal cylinder;

a piston slidingly retained within said cylinder, wherein a first side of said piston communicates with said hydraulic circuit and a second side of said piston communicates with said annulus;

a spring retained within said cylinder between a cylinder end and said second piston side, said spring exerting a pressure on said piston; and

wherein said piston communicates said annulus pressure and said spring pressure to said hydraulic circuit.

14. The apparatus of claim 13 wherein said hydraulic reservoir accumulator body comprises a plurality of locking wings and said recess comprises a plurality of L-shaped slots for receiving said locking wings.

15. The downhole apparatus of claim 12 wherein said drill collar outer surface comprises a recess for receiving said hydraulic reservoir accumulator, and said recess and said hydraulic reservoir accumulator to maintain said hydraulic circuit fluid pressure when said hydraulic reservoir accumulator is removed from said recess.

16. A method of operating a downhole apparatus comprising:

disposing a drill collar in a borehole, the drill collar comprising an extendable sample device, a hydraulic circuit and a draw down piston assembly;

extending a sampling member from the extendable sample device beyond the drill collar;

moving a piston of the draw down piston assembly;

drawing a fluid into the extendable sample device and a flow line connecting the extendable sample device and the draw down piston assembly;

accumulating a fluid pressure in the hydraulic circuit;

diverting a hydraulic fluid from a retract side of the sampling member;

directing the fluid to the extend side of the sampling member; and

providing an additional extending force to the extend side of the sampling member.

17. The method of claim 16 further comprising filtering the fluid drawn into the flow line.

18. The method of claim 17 further comprising measuring a property of the fluid drawn into the flow line.

19. The method of claim 16 further comprising:

disposing an equalizer valve in the drill collar, the equalizer valve in fluid communication with the flow line;

opening the equalizer valve; and

pumping the fluid in the flow line out through the equalizer valve to clean the flow line.

20. The method of claim 16 further comprising indicating a position of the draw down piston at any point during the draw down piston movement.

21. The method of claim 20 wherein indicating a position further comprises calculating a distance the draw down piston has moved using a known volume of fluid for moving the draw down piston and a known radius value of the draw down piston.

22. The method of claim 20 further comprising calculating a rate of draw down piston movement and correcting another downhole measurement.

23. The method of claim 20 wherein the draw down piston may be moved between a first and second position, further comprising:

stopping the draw down piston at a third position; and

re-starting movement of the draw down piston.

24. The method of claim 23 wherein the re-starting movement of the draw down piston occurs at a different rate than the moving a draw down piston.

25. The method of claim 23 further comprising:

purging a fluid from the extendable sample device; and

cleaning debris from the extendable sample device.

26. The method of claim 16 further comprising:

using an extend accumulator in the hydraulic circuit to accumulate a fluid pressure; and

providing an additional extending force to the extendable sample device.

27. The method of claim 16 further comprising:

using a retract accumulator in the hydraulic circuit to accumulate a fluid pressure; and

providing a retract force to the extendable sample device.

28. The method of claim 16 further comprising:

using a drawdown accumulator in the hydraulic circuit to accumulate a fluid pressure; and

providing a force to the draw down piston assembly.