METHODS AND APPARATUS OF DOWNHOLE FLUIDS ANALYSIS

• US 20090321072A1
• Filed: 06/30/2008
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Marpaung, Sihar, Yanase, Tsuyoshi, Kanayama, Kazumasa
• Granted Patent: US 8,109,157 B2
• Time in Patent Office: Days
• US Class Current: 166/250.01
• CPC Class Codes: E21B 49/10 using side-wall fluid samplers or testers

Abstract

A fluid sampling and analysis module for a downhole fluid characterization apparatus configured for operation downhole, within a borehole. The fluid sampling and analysis module comprises a primary flowline for fluids withdrawn from a formation to flow through the fluid sampling and analysis module, a bypass flowline in fluid communication with the primary flowline and a single valve, interconnecting the primary flowline and the bypass flowline, operable to a first position for formation fluids to flow in the primary flowline and to a second position for formation fluids to flow, via the bypass flowline, in the primary flowline.

Claims

1. A downhole fluid characterization apparatus configured for operation downhole, within a borehole, comprising:

a fluid sampling and analysis module, the fluid sampling and analysis module comprising;

a primary flowline for fluids withdrawn from a formation to flow through the fluid sampling and analysis module downhole, within a borehole, the primary flowline having a first end for the fluids to enter and a second end for the fluids to exit the fluid sampling and analysis module;

a bypass flowline in fluid communication with the primary flowline; and

a fluid control system interconnecting the primary flowline and the bypass flowline, the fluid control system having a first position interconnecting a first port of the primary flowline with a second port of the primary flowline for formation fluids to flow in the primary flowline, and a second position interconnecting the first port of the primary flowline with a first port of the bypass flowline and the second port of the primary flowline with a second port of the bypass flowline for formation fluids to flow, via the bypass flowline, in the primary flowline, wherein

fluid flow in the primary flowline is maintained during operation of the fluid control system between the first position and the second position.

2. The downhole fluid characterization apparatus according to claim 1, wherein

in the first position of the fluid control system, the bypass flowline comprises a circulation flowline for captured formation fluids to circulate in a closed loop of the circulation flowline.

3. The downhole fluid characterization apparatus according to claim 2, wherein

the fluid sampling and analysis module further comprising:

a circulation pump for circulating captured formation fluids in the closed loop of the circulation flowline.

4. The downhole fluid characterization apparatus according to claim 2, wherein

the fluid sampling and analysis module further comprising:

at least one first sensor structured and arranged for measuring parameters of interest downhole, within a borehole, wherein

the parameters of interest relate to captured formation fluids in the circulation flowline, and

the at least one first sensor comprising one or more of a density/viscosity sensor;

a pressure sensor; and

an imager.

5. The downhole fluid characterization apparatus according to claim 2, wherein

the fluid sampling and analysis module further comprising:

a pump unit in fluid communication with the bypass flowline for varying pressure and volume of captured fluids.

6. The downhole fluid characterization apparatus according to claim 1, wherein

the fluid sampling and analysis module further comprising:

a pressure compensation unit associated with the fluid control system, the pressure compensation unit being structured and arranged for balancing pressure at opposite ends of the fluid control system to borehole pressure.

7. The downhole fluid characterization apparatus according to claim 1, wherein

the fluid sampling and analysis module further comprising:

a plurality of sensors structured and arranged for measuring parameters of interest relating to fluids withdrawn from the formation.

8. The downhole fluid characterization apparatus according to claim 1, wherein

the fluid control system comprises:

a shaft structured and arranged for longitudinal movement in a housing;

the shaft having a through hole extending longitudinally and three orifices;

an annular space between the shaft and the housing, and four seals attached to the shaft in the annular space between the shaft and the housing, wherein

the shaft and the inner wall of the housing being shaped so that in combination with the three orifices, through hole and annular space between the shaft and the housing fluid flow in the primary flowline is not blocked during operation of the fluid control system between the first position and the second position.

9. A tool configured to be located downhole for sampling and characterizing formation fluids located downhole in an oilfield reservoir, comprising:

a fluid analysis module, the fluid analysis module comprising;

a flowline for fluids withdrawn from a formation to flow through the fluid analysis module, the flowline having a first end for the fluids to enter and a second end for the fluids to exit the fluid analysis module;

the flowline comprising;

a primary flowline and a bypass flowline; and

the fluid analysis module further comprising;

a single valve interconnecting the primary flowline and the bypass flowline, the single valve being operable to a first position for formation fluids to flow in the primary flowline, and to a second position for formation fluids to flow, via the bypass flowline, in the primary flowline, wherein;

the bypass flowline comprises a closed loop flowline for captured fluids when the valve is in the first position.

10. The tool according to claim 9, wherein

fluid flow in the primary flowline is maintained during operation of the valve between the first and the second positions.

11. The tool according to claim 9, wherein

the fluid analysis module further comprising:

a pressure compensation unit structured and arranged for balancing pressure at opposite ends of the valve so that operation of the valve between the first and the second positions is at a balanced borehole pressure.

12. A fluid flow control system structured to control flow of downhole fluids through a fluid sampling and analysis module configured for operation downhole, within a borehole, the fluid sampling and analysis module comprising a primary flowline and a bypass flowline, in fluid communication with the primary flowline, for downhole fluids withdrawn from a formation to flow through the fluid sampling and analysis module, the primary flowline having a first end for the fluids to enter and a second end for the fluids to exit the fluid sampling and analysis module, the fluid flow control system comprising:

a movable shaft configured and designed for operation downhole, within a borehole, the movable shaft being operable to selectively interconnect the primary flowline and the bypass flowline of the fluid sampling and analysis module, wherein

the movable shaft has a first operating position interconnecting a first port of the primary flowline with a second port of the primary flowline, and a second operating position interconnecting the first port of the primary flowline with a first port of the bypass flowline and the second port of the primary flowline with a second port of the bypass flowline, wherein

in the first position of the movable shaft downhole fluids flow in the primary flowline, and in the second position of the moveable shaft downhole fluids flow, via the bypass flowline, in the primary flowline; and

fluid flow in the primary flowline is maintained during operation of the movable shaft between the first and the second operating positions.

13. The fluid flow control system according to claim 12, further comprising:

a housing;

the movable shaft being structured and arranged in the housing for movement thereof in a longitudinal direction, wherein

the movable shaft has a central through hole through which the downhole fluids flow in a longitudinal direction thereof;

an annular space between an outer surface of the movable shaft and an inner surface of the housing; and

three orifices for directing flow of downhole fluids in the primary flowline and the bypass flowline, wherein

the shaft and the inner wall of the housing being shaped so that in combination with the three orifices, through hole and annular space between the shaft and the housing fluid flow in the primary flowline is not blocked during movement of the fluid control system between the first and the second operating positions.

14. The fluid flow control system according to claim 12, further comprising:

a pressure compensation unit structured and arranged for balancing pressure at opposite ends of the movable shaft so that operation of the moveable shaft between the first and the second operating positions is at a balanced borehole fluid pressure.

15. A method of downhole characterization of formation fluids utilizing a downhole tool comprising a fluid sampling and analysis module having a primary flowline, a bypass flowline and a single valve configured and designed for selectively interconnecting the primary flowline and the bypass flowline for flowing formation fluids through the fluid sampling and analysis module and for capturing formation fluids in a closed loop of the bypass flowline, the method comprising:

setting the valve in a first operating position so that formation fluids flow through the primary flowline;

monitoring at least a first parameter of interest relating to formation fluids flowing in the primary flowline;

when a predetermined criterion for the first parameter of interest is satisfied, setting the valve in a second operating position so that formation fluids flow, via the bypass flowline, in the primary flowline;

capturing formation fluids in the closed loop of the bypass flowline by returning the valve to the first operating position;

balancing pressure at opposite ends of the valve so that operation of the valve between the first and the second operating positions is at a balanced fluid pressure; and

characterizing captured formation fluids by operation of one or more sensor structured and arranged on the bypass flowline.

16. The method of downhole characterization of formation fluids according to claim 15, wherein

characterizing captured formation fluids includes determining one or more fluid property of the captured fluids.

17. The method of downhole characterization of formation fluids according to claim 16, wherein

determining one or more fluid property comprises changing fluid pressure of the captured formation fluids by varying volume of the captured fluids before determining one or more fluid property.

18. The method of downhole characterization of formation fluids according to claim 17, wherein

the one or more fluid property determined after changing fluid pressure includes one or more of fluid compressibility;

asphaltene precipitation onset;

bubble point; and

dew point.

19. The method of downhole characterization of formation fluids according to claim 15, further comprising:

circulating captured formation fluids in the closed loop of the bypass flowline while characterizing the captured fluids.

20. The method of downhole characterization of formation fluids according to claim 19, wherein

characterizing the captured formation fluids includes determining phase behavior of the fluids while circulating the captured formation fluids in the closed loop.