Weight-based phase composition ratio determination

Patent metadata

Field	Value
Publication number	US-10281310-B2
Application number	US-201715464168-A
Country	US
Kind code	B2
Filing date	Mar 20, 2017
Priority date	Sep 24, 2014
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

Several embodiments include a method of computing a phase composition ratio of a two-phase mixture in a pipe. For example, the phase composition ratio is a void fraction or a dryness fraction. The two-phase mixture can have one or more material substances that do not travel as a whole (e.g., at least two of solid phase, liquid phase, and gaseous phase or two liquid materials of different densities that do not mix). A load cell can measure, continuously, weight of the pipe and content of the pipe. Then, a computing system or a circuit can compute, continuously, a moving average of the continuously measured weight. The computing system or the circuit can compute a change in the phase composition ratio of the two-phase mixture based on the computed moving average.

First claim

What is claimed is:

1. A method comprising
continuously measuring weight of a pipe and content of the pipe during production operation of a geothermal well, wherein the pipe conveys a two-phase mixture extracted from the geothermal well, and wherein the two-phase mixture has one or more material substances in at least two of solid phase, liquid phase, and gaseous phase;
continuously computing a moving average of the measured weight; and
computing, in real-time, a change in a phase composition ratio of the two-phase mixture based on the computed moving average, where in the phase composition ratio is a void fraction or a dryness fraction.

2. The method of claim 1 , further comprising estimating the phase composition ratio based on the change in the phase composition ratio and an initial phase composition ratio value.

3. The method of claim 2 , further comprising computing enthalpy in the two-phase mixture based on the estimated phase composition ratio.

4. The method of claim 3 , further comprising dynamically adjusting a steam field of a geothermal power plant based on the computed enthalpy.

5. The method of claim 1 , further comprising:
continuously computing a statistical spread measure curve based on the continuously measured weight; and
detecting a slug flow event in the pipe by determining whether the statistical spread measure curve is above a minimum standard deviation level.

6. The method of claim 5 , wherein the statistical spread measure curve is a standard deviation curve or a variance curve.

7. The method of claim 5 , further comprising:
sending an alert message upon the detecting of the slug flow event.

8. The method of claim 1 , wherein the weight of the pipe is a first weight at a first portion of a pipe system including the pipe; and the method further comprises:
measuring continuously a second weight at a second portion of the pipe system downstream from the pipe; and
computing a flow speed of the two-phase mixture by comparing patterns of the first weight and the second weight within consecutive time windows.

9. The method of claim 1 , further comprising:
determining a temperature reading within or at the pipe;
computing a pipe stress adjustment based on variation in the temperature reading; and
normalizing the weight against the pipe stress adjustment.

10. The method of claim 1 , further comprising:
measuring a pressure reading within the pipe;
computing a pipe stress adjustment based on variation in the pressure reading; and
normalizing the weight against the pipe stress adjustment.

11. The method of claim 1 , further comprising:
continuously monitoring flow velocity of the content of the pipe; and
detecting an indication of an onset of slug flow or a cyclical pattern of slug flow based on data related to the flow velocity and data related to the void fraction or the dryness fraction.

12. The method of claim 11 , further comprising:
time-stamping or tagging data associated with the indication of the onset of slug flow or the cyclical pattern of slug flow.

13. A phase composition monitor comprising
a load cell adapted to couple with a support stand of a pipe and to take weight measurements of the pipe and a two-phase mixture content transported by the pipe;
a transceiver configured to transmit the weight measurements to a computing system; and
the computing system configured to compute a change in a quantitative ratio between two phases or two materials of the two-phase mixture content based on variation of the weight measurements, wherein the quantitative ratio is based on mass or on volume.

14. The phase composition monitor of claim 13 , wherein the transceiver is a wireless transceiver.

15. The phase composition monitor of claim 13 , wherein the computing system is configured to compute, in real-time, an absolute quantitative ratio based on the computed change in the quantitative ratio and an initial value of the quantitative ratio.

16. The phase composition monitor of claim 13 , wherein the load cell is configured to interface with a pipe support cradle of the support stand.

17. The phase composition monitor of claim 16 , wherein the load cell includes a roller adapted to interface with the pipe support cradle.

18. The phase composition monitor of claim 17 , wherein the roller is adapted with a pivot mechanism.

19. The phase composition monitor of claim 13 , wherein the load cell is adapted to be fastened, strapped, and/or attached to the support stand.

20. The phase composition monitor of claim 13 , further comprising one or more adjustable length legs that supports the load cell.

21. The phase composition monitor of claim 13 , wherein the load cell is a first load cell and the weight measurements are a first set of weight measurements; and the phase composition monitor further comprises a second load cell adapted to take second set of weight measurements at a portion of the pipe different from where the first load cell is taking the first set of weight measurements.

22. The phase composition monitor of claim 21 , wherein the computing system is configured to compute a flow speed of the two-phase mixture by comparing patterns of the first set and the second set within consecutive time windows.

23. The phase composition monitor of claim 13 , wherein the computing system is configured to compute a statistical spread measure curve based on the weight measurements and to detect a slug flow event in the pipe by determining whether the statistical spread measure curve is above a minimum standard deviation level.

24. The phase composition monitor of claim 23 , further including:
an orifice plate adapted to couple with the pipe and to continuously monitor flow velocity of the content of the pipe, wherein the computing system is configured to detect an indication of an onset of the slug flow event based on data related to the flow velocity and data related to the void fraction or the dryness fraction.

25. The phase composition monitor of claim 24 , wherein the computing system is configured to time-stamp or tag monitoring data associated with the indication of the onset of the slug flow event to enable a comparison of the monitoring data with other data derived from a phenomenon associated with a geothermal well that is being monitored by the phase composition monitor.

26. The phase composition monitor of claim 13 , wherein the computing system is configured to send an alert upon detection of a slug flow event.

27. A geothermal power plant comprising:
a pipe system adapted to convey a two-phase mixture of vapor and brine;
one or more support stands along the length of the pipe system;
one or more load cells coupled to the pipe system to measure changes in weight of one or more sections of the pipe system between pairings of the support stands; and
a computing device configured to compute a quantitative ratio between two phases of the two-phase mixture based on the changes in the weight, wherein the quantitative ratio is based on mass or on volume.

28. The geothermal power plant of claim 27 , further comprising: an extraction unit operatively coupled to a geothermal well to extract the two-phase mixture; and wherein the pipe is operatively coupled to the extraction unit.

29. The geothermal power plant of claim 27 , further comprising: a generator unit, operatively coupled to the pipe, co

Assignees

• Sisler John R
• Boetzer Kenneth D
• Zarrouk Sadiq Jafar Mohammed
• Auckland Uniservices Ltd
• Steamfield Sensors Inc

Inventors

• Sisler John R
• Boetzer Kenneth D
• Zarrouk Sadiq Jafar Mohammed

Classifications

• G01F1/74 Primary

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

• G01F1/36

  the pressure or differential pressure being created by the use of flow constriction · CPC title

• E21B47/0003

  Fixed Constructions · mapped topic

• G01G1/00

  Weighing apparatus involving the use of a counterweight or other counterbalancing mass · CPC title

• G01N33/246

  for water content · CPC title