SYSTEM AND METHOD FOR SPOT CHECK ANALYSIS OR SPOT SAMPLING OF A MULTIPHASE MIXTURE FLOWING IN A PIPELINE

• US 20100145634A1
• Filed: 03/19/2008
• Published: 06/10/2010
• Est. Priority Date: 03/27/2007
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Pinguet, Bruno, Birkett, Graham, Guieze, Paul, Xie, Cheng-gang
• Granted Patent: US 8,606,531 B2
• Time in Patent Office: Days
• US Class Current: 702/45
• CPC Class Codes: G01F 1/46 Pitot tubes
• CPC Class Codes: G01F 1/74 Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid
• CPC Class Codes: G01N 1/2035 by deviating part of a fluid stream, e.g. by drawing-off or tapping
• CPC Class Codes: G01N 33/2823 raw oil, drilling fluid or polyphasic mixtures hydrocarbon content of earth materials G01N33/241; prospecting G01V; drilling per se E21B
• CPC Class Codes: G01N 35/08 using a stream of discrete samples flowing along a tube system, e.g. flow injection analysis

Abstract

This disclosure relates in general to systems and methods for spot checking flow properties of a multiphase mixture containing one or more hydrocarbons flowing through a pipeline or the like. More specifically, but not by way of limitation, embodiments of the present invention provide systems and methods for creating slug-type flows of isokinetically obtained samples of the multiphase mixture flow. By spot checking the slug-type flow of an isokinetically obtained sample of the multiphase flow, embodiments of the present invention may provide for determining flow properties of gas, oil/condensate and/or water components of the multiphase flow. In certain aspects of the present invention, an active sampling device may be used to enrich one of the phases of the slug-type flow of the sampled multiphase mixture and/or take a representative sample of one of the phases of the slug-type flow of the sampled multiphase mixture.

Claims

1. A method for spot check analysis or spot sampling of a multiphase mixture flowing in a pipeline, comprising:

collecting a sample of the multiphase mixture under isokinetic conditions, wherein the multiphase mixture comprises a mixture of one or more different phases, and wherein a phase comprises one of a liquid phase, a gas phase, a water phase, an oil phase and an oil/condensate phase;

flowing the collected sample in a phase separated or slug-type flow; and

detecting a presence of each phase of the one or more different phases of the phase separated or slug-type flow at a phase detection location.

2. The method of claim 1, further comprising:

conditioning the multiphase mixture flowing in the pipeline upstream of a sampling cross-section, wherein the sampling location is a cross-section of the pipeline from which the sample is retrieved.

3. The method of claim 1, further comprising:

using temporal measurements for each phase of the one or more different phases of the phase separated or slug-type flow detected at the phase detection location to process a phase fraction for each phase of the one or more different phases of the phase separated or slug-type flow detected at the phase detection location.

4. The method of claim 1, further comprising:

using the processed phase fraction for each phase of the one or more different phases of the phase separated or slug-type flow detected at the phase detection location to determine one of a water-liquid ratio, a gas-oil/condensate ratio and a gas-liquid ratio.

5. The method of claim 1, further comprising:

outputting data from the phase detection location regarding a presence of a single phase of the multiphase mixture at the detection location; and

using the output data to selectively sample the single phase.

6. The method of claim 1, further comprising:

determining a velocity of the collected sample; and

using the processed phase fraction, the velocity and a sample conduit cross-sectional area to determine one of a volume flow rate of the collected sample, a liquid volume flow rate of the liquid phase, a gas volume flow rate of the gas phase, a water volume flow rate of the water phase and an oil volume flow rate of the oil phase, wherein the sample conduit cross-sectional area is a cross-sectional area of a conduit containing the flowing collected sample.

7. The method of claim 1, further comprising:

using one of the volume flow rate, the liquid volume flow rate, the gas volume flow rate, the water volume flow rate and the oil volume flow rate and a ratio between the sample conduit cross-sectional area and a pipeline cross-sectional to determine one of a total volume flow rate of the multiphase mixture in the pipeline, a total liquid volume flow rate of the liquid phase in the pipeline, a total gas volume flow rate of the gas phase in the pipeline, a total water volume flow rate of the water phase in the pipeline and a total oil volume flow rate of the oil phase in the pipeline, wherein the pipeline cross-sectional is a cross-section area of the pipeline at a location in the pipeline from which the sample was collected.

8. A system for spot check analysis or spot sampling of a multiphase mixture flowing in a pipeline, comprising:

means for sampling the multiphase mixture under isokinetic conditions;

means for flowing the sample of the multiphase mixture in a phase separated or slug-type flow; and

means for detecting a presence of a phase of the phase separated or slug-type flow at a phase detection location.

9. The system of claim 8, further comprising:

means for conditioning the multiphase mixture in the pipeline upstream of the means for sampling.

10. The system of claim 9, further comprising:

means for processing output data from the means for detecting the presence of the phase of the phase separated or slug-type flow to determine a phase fraction for the detected phase.

11. The system of claim 10, further comprising:

means for determining a velocity of the flowing sample; and

means for processing the phase fraction, the velocity and a sample cross-sectional area to determine a volume flow rate for the detected phase in the means for flowing, wherein the sample cross-sectional area comprises a cross-sectional area of the means for flowing the sample.

12. The system of claim 10, further comprising:

means for processing the volume flow rate and a ratio between the sample cross-sectional area and a pipeline cross-sectional area to determine a total volume flow rate of the detected phase in the pipeline, wherein the pipeline cross-sectional area comprises a cross-sectional area of the pipeline at a location of the means for sampling.

13. The system of claim 10, further comprising:

means for obtaining a portion of the flowing sample.

14. The system of claim 13, further comprising:

means for controlling the means for obtaining the portion of the flowing sample, wherein the means for controlling is coupled with the means for detecting to provide that the means for obtaining the portion of the flowing sample is controlled to only obtain a portion of the detected phase.

15. A system for spot check analysis or spot sampling of a multiphase mixture flowing in a pipeline, comprising:

a sampling probe for retrieving a sample of the multiphase mixture from a sampling location in the pipeline;

a differential pressure sensor configured to determine a differential pressure between a pipeline pressure of the multiphase mixture at the sampling location and a probe pressure of the sample in the probe;

one or more valves coupled with the sampling probe;

a processor coupled with the differential pressure sensor and the one or more valves and configured to control the one or more valves to provide that the sample is obtained under isokinetic conditions by nulling the differential pressure; and

a conduit coupled with the sampling probe and configured to provide that the sample flows through the conduit in a slug-type flow.

16. The system of claim 15, further comprising:

a flow conditioner coupled with the pipeline upstream of the sampling location and configured to condition the multiphase mixture.

17. The system of claim 15, further comprising:

a first phase detector coupled with the conduit at a first phase detection location and configured to detect a first phase of the sample flowing in the conduit at the first phase detection location.

18. The system of claim 17, further comprising:

a sampling device coupled with the conduit and disposed downstream of the phase detector.

19. The system of claim 18, further comprising:

a sampling processor coupled with the phase detector and the sampling device and configured to control the sampling device to collect a phase sample of the detected phase.

20. The system of claim 15, further comprising:

a fraction processor coupled with the phase detector and configured to determine a phase fraction for the detected phase from temporal measurements.

21. The system of claim 18, further comprising:

a flow meter coupled with the sampling probe or the conduit and configured to determine a flow rate of the sample.

22. The system of claim 17, further comprising:

a second phase detector coupled with the conduit at a second phase detection location and configured to detect a second phase of the sample at the second phase location, wherein the first detection location and the second phase location are separated by a known distance.

23. The system of claims 21, further comprising:

a flow processor coupled with the first phase detector and the flow meter and configured to determine one of a volume flow rate of the detected phase in the conduit and a total flow rate of the detected phase in the pipeline.

24. The system of claims 21, further comprising:

a flow processor coupled with the first phase detector and the second flow detector and configured to determine one of a volume flow rate of the detected phase in the conduit and a total flow rate of the detected phase in the pipeline.

25. The system of claims 17, wherein the first phase detector is one of an optical sensor, an electrical sensor, a microwave sensor, and a millimetre-wave sensor, a nuclear sensor, an acoustic sensor.

26. The system of claims 15, wherein the conduit has an internal diameter of less than 10 mm.