Flow regime recognition for flow model adaptation

Patent metadata

Field	Value
Publication number	US-2016290841-A1
Application number	US-201415034759-A
Country	US
Kind code	A1
Filing date	Nov 7, 2014
Priority date	Nov 8, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

A sensor of a multiphase flow meter is operated to determine a physical property attributable to multiphase fluid flow in a conduit of the multiphase flow meter. A stationarity of the multiphase fluid flow is determined based on the determined physical property in actual conditions compared to expected noise of the sensor in stationary flow conditions. A flow model variable is selected from a plurality of flow model variables based on a gas content of the multiphase fluid flow and the determined stationarity. The multiphase fluid flow is then modeled by adjusting the selected flow model variable.

First claim

1 . A method, comprising:
operating a sensor of a multiphase flow meter to determine a physical property attributable to multiphase fluid flow in a conduit of the multiphase flow meter; determining a stationarity of the multiphase fluid flow based on the determined physical property in actual conditions compared to expected noise of the sensor in stationary flow conditions; selecting a variable from a plurality of variables based on a gas content of the multiphase fluid flow and the determined stationarity; and modeling the multiphase fluid flow by adjusting the selected variable.

2 . The method of claim 1 wherein the sensor comprises a nuclear sensor and the physical property is attenuation.

3 . The method of claim 1 , wherein the sensor comprises a venturi differential-pressure sensor and the physical property is differential pressure data.

4 . The method of claim 1 further comprising determining the expected noise.

5 . The method of claim 1 further comprising determining a flow regime of the multiphase fluid flow based on the gas content and the determined stationarity.

6 . The method of claim 5 wherein determining the flow regime comprises selecting the flow regime from a predetermined plurality of possible flow regimes.

7 . The method of claim 6 wherein the predetermined plurality of possible flow regimes comprises:
a bubble flow regime in which the multiphase fluid flow has a gas volume fraction (GVF) less than about 20% and bubble sizes less than about 10% of a diameter of the conduit;
a slug flow regime in which the multiphase fluid flow comprises a succession of gas pockets and liquid plugs alternatingly occupying a substantial portion of the diameter of the conduit; and
a wet gas flow regime in which the multiphase fluid flow has a GVF of at least about 85% and substantially lacks liquid plugs.

8 . The method of claim 1 wherein the sensor comprises a nuclear source operable to emit nuclear energy through the conduit to an opposing nuclear detector, and wherein determining the physical property attributable to the multiphase fluid flow utilizes statistical data based on nuclear energy detected by the nuclear detector.

9 . The method of claim 8 wherein the nuclear energy detected by the detector comprises nuclear energy emitted from the nuclear source at each of a plurality of different energy levels.

10 . The method of claim 1 further comprising:
determining a gas hold-up (GHU) of the multiphase fluid flow; and
determining the gas content of the multiphase fluid flow based on the determined GHU.

11 . The method of claim 10 wherein selecting the variable from the plurality of variables based on the determined gas content and the determined stationarity comprises at least one of:
selecting a first variable if the determined gas content is less than a predetermined GHU threshold;
selecting the first variable for adjustment if the determined gas content is greater than the predetermined GHU threshold and the determined stationarity indicator is less than a first predetermined stationarity indicator threshold;
selecting a second variable for adjustment if the determined gas content is greater than the predetermined GHU threshold and the determined stationarity indicator is greater than a second predetermined stationarity indicator threshold; and
selecting a third variable for adjustment if the determined gas content is greater than the predetermined GHU threshold and the determined stationarity indicator is between the first and second predetermined stationarity indicator threshold.

12 . The method of claim 11 further comprising at least one of:
determining that the multiphase fluid flow is substantially stationary if the determined stationarity indicator is below the first predetermined stationarity indicator threshold;
determining that the multiphase fluid flow is substantially nonstationary if the determined stationarity indicator is above the second predetermined stationarity indicator; and
determining that the multiphase fluid flow is in transition between substantially stationary and substantially nonstationary if the determined stationarity indicator is between the first and second predetermined stationarity indicator thresholds.

13 . The method of claim 11 wherein the third variable is a combination of the adjustment of the first and second variables.

14 . The method of claim 13 wherein the combination of the adjustment of the first and second variables is a combination proportional to differences between the determined stationarity indicator and the first and second predetermined stationarity indicator thresholds.

15 . The method of claim 13 wherein the combination of the adjustment of the first and second variables is based on a function of the determined stationarity indicator.

16 . An apparatus, comprising:
a multiphase flow meter comprising:
a conduit containing a multiphase fluid flow;
a nuclear source; and
a nuclear detector operable to detect nuclear energy emitted by the nuclear source through the conduit and multiphase fluid flow; and
an electronic instrument operable for:
determining a flow regime and a gas content of the multiphase fluid flow based on nuclear energy detected by the detector compared to expected noise of the nuclear detector in stationary flow conditions;
determining a stationarity of the multiphase fluid flow based on the determined flow regime;
selecting a variable from a plurality of variables based on the determined gas content and the determined stationarity; and
modeling the multiphase fluid flow by adjusting the selected variable.

17 . The apparatus of claim 16 further comprising tubing extending from a production zone of a wellbore penetrating a subterranean formation, wherein the tubing is in fluid communication with the conduit.

18 . A method, comprising:
determining which of a plurality of flow model variables an electronic instrument is adjusting to determine flow rates of each phase constituent of multiphase fluid flow within a conduit of a flow meter; operating the flow meter to determine a flow regime and a gas content of the multiphase fluid flow within the conduit; determining an indicator of stationarity of the multiphase fluid flow based on the determined flow regime and the determined gas content; and changing which of the plurality of flow model variables the electronic instrument adjusts to determine flow rates of each phase constituent of the multiphase fluid flow based on the determined gas content and the determined stationarity indicator.

19 . The method of claim 18 wherein changing which of the plurality of flow model variables the electronic instrument utilizes comprises changing from a first variable to a second variable.

20 . The method of claim 18 wherein changing which of the plurality of flow model variables the electronic instrument adjusts comprises changing from a first flow model variable to a combined adjustment of the first flow model variable and a second flow model variable.

Assignees

• Schlumberger Technology Corp

Inventors

• Cadalen Sebastien
• Fournier Benoit

Classifications

• G01F1/44 Primary

  Venturi tubes · CPC title

• G01F1/58 Primary

  by electromagnetic flowmeters · CPC title

• G01F1/74

  Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid · CPC title

• G01V5/08

  using primary nuclear radiation sources or X-rays {(, e.g. for inducing radioactivity; investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays, neutrons G01N23/00)} · CPC title

• E21B49/08

  Obtaining fluid samples or testing fluids, in boreholes or wells · CPC title