Methods and apparatus of downhole fluid analysis

• US 20060243047A1
• Filed: 08/15/2005
• Published: 11/02/2006
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Terabayashi, Toru, Mullins, Oliver C., Yamate, Tsutomu, Kurkjian, Andrew L., Chikenji, Akihito, Elshahawi, Hani
• Granted Patent: US 7,461,547 B2
• Time in Patent Office: Days
• US Class Current: 73/152.550
• CPC Class Codes: E21B 49/10 using side-wall fluid samplers or testers
• CPC Class Codes: G01N 2011/006 Determining flow properties indirectly by measuring other parameters of the system
• CPC Class Codes: G01N 9/36 Analysing materials by measuring the density or specific gravity, e.g. determining quantity of moisture methods of measurement in general G01N9/02 - G01N9/32

Abstract

Methods and apparatus for downhole analysis of formation fluids by isolating the fluids from the formation and/or borehole in a pressure and volume control unit that is integrated with a flowline of a fluid analysis module and determining fluid characteristics of the isolated fluids. Parameters of interest may be derived for formation fluids in a static state and undesirable formation fluids may be drained and replaced with formation fluids that are suitable for downhole characterization or surface sample extraction. Isolated formation fluids may be circulated in a loop of the flowline for phase behavior characterization. Real-time analysis of the fluids may be performed at or near downhole conditions.

Claims

1. A downhole fluid characterization apparatus, 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a flowline for fluids withdrawn from a formation to flow through the fluid analysis module, the flowline having a first end for the fluids to enter and a second end for the fluids to exit the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;

a first selectively operable device and a second selectively operable device structured and arranged with respect to the flowline for isolating a quantity of the fluids in a portion of the flowline between the first and second selectively operable device; and

at least one sensor situated on the portion of the flowline between the first and second selectively operable device for measuring parameters of interest relating to the fluids in the flowline.

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

at least one of the first and second selectively operable device comprises a valve.

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

one of the first and second selectively operable device comprises a pump and the other of the first and second selectively operable device comprises a valve.

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

the pump is in a pumpout module of the downhole fluid characterization apparatus.

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

the fluid analysis module further comprising:

a pump unit integrated with the flowline for varying pressure and volume of the isolated fluids.

6. The downhole fluid characterization apparatus according to claim 5, wherein the pump unit comprises a syringe-type pump.

7. The downhole fluid characterization apparatus according to claim 1, wherein the at least one sensor comprises a plurality of sensors.

8. The downhole fluid characterization apparatus according to claim 1, wherein the at least one sensor comprises one or more of a spectral sensor optically coupled to the flowline;

a fluorescence and gas sensor;

a density sensor;

a pressure sensor;

a temperature sensor;

a bubbles/gas sensor;

a MEMS based sensor;

an imager;

a resistivity sensor;

a chemical sensor; and

a scattering sensor.

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

the portion of the flowline for isolating the fluids comprising:

a bypass flowline, the first and second selectively operable device being structured and arranged for isolating fluids in the bypass flowline, and

a circulation line interconnecting a first end of the bypass flowline with a second end of the bypass flowline such that fluids isolated between the first and second selectively operable device can circulate in a closed loop formed by the circulation line and the bypass flowline; and

the fluid analysis module further comprising;

a circulation pump for circulating fluids in the closed loop of the circulation line and the bypass flowline.

10. The downhole fluid characterization apparatus according to claim 9, wherein

the at least one sensor comprises one or more of a density sensor;

a pressure sensor;

a temperature sensor;

a bubbles/gas sensor;

a MEMS based sensor;

an imager; and

a scattering sensor, wherein the at least one sensor measures parameters of interest relating to fluids isolated in the bypass flowline; and

the fluid analysis module further comprising;

one or more of a spectral sensor optically coupled to the flowline;

a fluorescence and gas sensor;

a chemical sensor; and

a resistivity sensor, structured and arranged with respect to the flowline for measuring parameters of interest relating to fluids flowing through the flowline.

11. A method of downhole characterization of formation fluids utilizing a downhole tool comprising a fluid analysis module having a flowline for flowing formation fluids through the fluid analysis module, the method comprising:

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

when a predetermined criterion for the first parameter of interest is satisfied, restricting flow of the formation fluids in the flowline by operation of a first selectively operable device and a second selectively operable device of the fluid analysis module to isolate formation fluids in a portion of the flowline of the fluid analysis module between the first and second selectively operable device; and

characterizing the isolated fluids by operation of one or more sensor on the flowline between the first and second selectively operable device.

12. The method of downhole characterization of formation fluids according to claim 11, wherein

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

13. The method of downhole characterization of formation fluids according to claim 12, wherein

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

14. The method of downhole characterization of formation fluids according to claim 13 further comprising:

monitoring time dependent signals in the one or more sensor on the flowline to detect gravity separation of the isolated fluids.

15. The method of downhole characterization of formation fluids according to claim 13, 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.

16. The method of downhole characterization of formation fluids according to claim 11 further comprising

circulating the isolated fluids in a closed loop of the flowline while characterizing the isolated fluids.

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

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

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

determining phase behavior of the isolated fluids comprises monitoring time dependent sensor properties to detect gravity separation of the phases.

19. A tool for 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 bypass flowline and a circulation line interconnecting a first end of the bypass flowline with a second end of the bypass flowline such that fluids can circulate in the circulation line and the bypass flowline; and

the fluid analysis module further comprising;

a circulation pump for circulating fluids in the circulation line and the bypass flowline;

at least one sensor situated on the bypass flowline for measuring parameters of interest relating to the fluids in the bypass flowline; and

a first selectively operable device and a second selectively operable device structured and arranged with respect to the flowline for isolating a quantity of the fluids in the bypass flowline between the first and second selectively operable device.

20. The tool for characterizing formation fluids in accordance with claim 19, wherein

the at least one sensor comprises one or more of a density sensor;

a pressure sensor;

a temperature sensor;

a bubbles/gas sensor;

a MEMS based sensor;

an imager; and

a scattering sensor, wherein the at least one sensor measures parameters of interest relating to fluids isolated in the bypass flowline; and

the fluid analysis module further comprising;

one or more of a spectral sensor optically coupled to the flowline;

a fluorescence and gas sensor;

a chemical sensor; and

a resistivity sensor, structured and arranged with respect to the flowline for measuring parameters of interest relating to fluids flowing through the flowline.

21. The tool for characterizing formation fluids in accordance with claim 20, wherein

at least one of the first and second selectively operable device comprises a valve;

and

the fluid analysis module further comprising;

a pump unit integrated with the flowline for varying pressure and volume of the isolated fluids.