Method and apparatus for storing energy and multiplying force to pressurize a downhole fluid sample

• US 20060076144A1
• Filed: 10/12/2005
• Published: 04/13/2006
• Est. Priority Date: 10/13/2004
• Status: Active Grant

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Shammai, Michael, Bullock, Harry Wade, Sanchez, Francisco Galvan
• Granted Patent: US 7,258,167 B2
• Time in Patent Office: Days
• US Class Current: 166/370
• CPC Class Codes: E21B 49/081 with down-hole means for trapping a fluid sample E21B49/10 takes precedence
• CPC Class Codes: E21B 49/082 Wire-line fluid samplers E21B49/083 takes precedence
• CPC Class Codes: E21B 49/10 using side-wall fluid samplers or testers

Abstract

A method and apparatus store energy in an energy storage medium located in an energy storage chamber. As a sampling tool descends into the borehole, the energy storage medium is pressurized with hydrostatic pressure. A sample is collected in a sample chamber by pumping formation fluid into the sample chamber against hydrostatic pressure. The energy storage medium applies the energy stored in the energy storage medium to the sample through a pressure communication member. A pressure multiplier member increases the pressure applied on the sample by the energy storage medium through the pressure communication member to keep pressure on the sample. A biasing water pressure is applied to the sample at the surface so that the energy storage chamber can be removed from the sample chamber.

Claims

1. An apparatus for pressurizing a sample downhole comprising:

a sample chamber that contains the sample, the sample chamber having a moveable sample chamber piston in pressure communication with hydrostatic pressure on a lower side of the sample chamber piston and in pressure communication with the sample on an upper side of the sample chamber piston;

an energy storage chamber containing an energy storage medium, the energy storage chamber having an energy storage piston in pressure communication with the sample chamber; and

a pressure communication member posited between the sample chamber piston and the energy storage piston.

2. The apparatus of claim 1, further comprising:

an energy bias chamber that applies hydrostatic pressure to the energy storage medium.

3. The apparatus of claim 1, further comprising:

a sample bias chamber that applies hydrostatic pressure to the sample.

4. The apparatus of claim 1, wherein the energy storage piston has a surface area different than a surface area of the sample chamber piston.

5. The apparatus of claim 1, wherein the energy storage piston has a surface area larger than a surface area of the sample chamber piston.

6. The apparatus of claim 1, wherein the sample comprises at least one of the set consisting of a fluid and a gas.

7. The apparatus of claim 1, further comprising:

a pressure chamber in pressure communication with the sample which accepts a pressurizing fluid to pressurize the sample chamber to enable removal of the energy storage chamber from pressure communication with the sample chamber.

8. A system for pressurizing a sample downhole comprising:

a downhole tool having a pump that transfers the sample into a sample chamber against a moveable sample chamber piston, wherein the sample chamber piston is in pressure communication with hydrostatic pressure on a lower side of the sample chamber piston and in pressure communication with the sample in the sample chamber on an upper side of the sample chamber piston;

an energy storage chamber containing an energy storage medium, the energy storage chamber having an energy storage piston in pressure communication with the sample in the sample chamber; and

a pressure communication member posited between the sample chamber piston and the energy storage piston.

9. The system of claim 8, further comprising:

an energy bias chamber that applies hydrostatic pressure to the energy storage medium.

10. The system of claim 8, further comprising:

a sample bias chamber that applies hydrostatic pressure to the sample.

11. The system of claim 8, wherein the energy storage piston has a surface area different than a surface area of the sample piston

12. The system of claim 8, wherein the energy storage piston has a surface area larger than a surface area of the sample chamber piston.

13. The system of claim 8, wherein the sample comprises at least one of the set consisting of a fluid and a gas.

14. The system of claim 8, further comprising:

a pressure chamber which accepts a pressurizing fluid to pressurize the sample chamber to enable removal of the energy storage chamber from pressure communication with the sample chamber.

15. A method for pressurizing a sample downhole comprising:

pumping the sample into a sample chamber against a hydrostatic pressure;

pressurizing an energy storage medium with the hydrostatic pressure;

placing the sample in the sample chamber and the energy storage medium in pressure communication; and

pressurizing the sample with the pressure in the energy storage medium.

16. The method of claim 15, further comprising:

pressurizing the energy storage medium to an initial pressure.

17. The method of claim 15, further comprising:

pressurizing the sample chamber with hydrostatic pressure.

18. The method of claim 15, further comprising:

Pressurizing the sample chamber with a multiple of hydrostatic pressure.

19. The method of claim 15, further comprising:

removing the hydrostatic pressure from the sample and the energy storage medium; and

applying a multiple of pressure stored in the energy storage medium to the sample in the sample chamber.

20. A method of pressurizing a formation fluid downhole comprising:

storing a compressible fluid in a first chamber;

pumping the formation fluid in a second chamber against a hydrostatic pressure;

establishing a pressure communication between the compressible fluid and the formation fluid;

compressing the compressible fluid to the hydrostatic pressure;

applying a pressure on the formation fluid that is greater than the hydrostatic pressure utilizing pressure of the compressible fluid.

21. The method of claim 20 wherein establishing the pressure communication further comprises establishing a mechanical link between the fluids in the first and second chambers.

22. The method of claim 20 further comprising:

maintaining pressure on the formation fluid in the first chamber and the compressible fluid in the second chamber at the hydrostatic pressure at a first depth in a wellbore;

applying the pressure greater than the hydrostatic pressure to the formation fluid in the second chamber at a second depth in the wellbore.

23. The method of claim 20 wherein the pressure greater than the hydrostatic pressure is a multiplier of the hydrostatic pressure.

24. The method of claim 20 further comprising:

defining the multiplier by a ratio of surface areas associated with the first and second chambers.