Clamp-on Multiphase Flow Metering via Ultrasonic Speed of Sound
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Solution Overview
Problem
Current flow measurement technologies in the oil and production field face inaccuracies due to the presence of entrained gases in crude oil, leading to incorrect liquid and gas volume determinations, and watercut measurements, as they struggle to ensure complete separation of gas and liquid phases, and have limitations in the number of measurement points and device reliability.
Innovation Solution
A clamp-on apparatus equipped with an array of strain-based sensors and ultrasonic sensors that measure the speed of sound and pressure disturbances in multiphase flows, allowing for the determination of gas volume fraction, watercut, and volumetric flow rates by distinguishing between sub-resonant and super-resonant frequencies to accurately characterize aerated fluid flows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional flow measurement technologies are used, then the measurement process is simple, but the measurement precision deteriorates due to the presence of entrained gases in crude oil
Solution Approach 1:
The measurement system is segmented into multiple independent measurement points along the flow path, with each point containing separate sensors for liquid volume, gas volume, and watercut measurements. This segmentation allows the system to handle multiphase flow by measuring each phase independently at multiple locations, thereby improving overall measurement precision without requiring a single complex measurement device.
Solution Approach 2:
The measurement system is designed with multi-functional capability to simultaneously measure liquid volumetric flow rate, gas volumetric flow rate, and watercut at each measurement point. By integrating multiple measurement functions into a unified system that can operate at multiple points along the flow path, the patent achieves high measurement precision for multiphase flow without proportionally increasing device complexity.
2Measurement precision
If more measurement points are added to improve measurement precision, then the measurement precision improves, but the device complexity and installation requirements increase
Solution Approach 1:
The system divides the measurement function into discrete, independent measurement points that can be distributed along the flow path. Each measurement point is a self-contained unit with standardized sensors and processing capabilities, allowing the system to achieve high precision through spatial segmentation without creating excessive complexity in any single location.
Solution Approach 2:
The system utilizes changes in flow parameters (such as velocity, pressure, and phase distribution) at different measurement points to characterize multiphase flow. By measuring how these parameters vary spatially, the system can determine accurate volumetric flow rates and watercut values without requiring overly complex measurement configurations at each point.
3Productivity
If gas and liquid phases are not completely separated, then the flow measurement can be performed, but the measurement precision deteriorates due to inaccurate liquid and gas volume determinations
Solution Approach 1:
The measurement system segments the multiphase flow measurement into separate measurement components for liquid volume, gas volume, and watercut at each measurement point. This segmentation enables the system to measure each phase independently even when complete phase separation does not occur, maintaining continuous measurement capability while improving accuracy through independent phase measurement.
Solution Approach 2:
The system incorporates feedback mechanisms that continuously monitor and adjust measurements based on the detected phase distribution. By using feedback from sensors to refine the measurement of liquid and gas volumes in real-time, the system can compensate for incomplete phase separation and maintain high measurement precision throughout the flow measurement process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The apparatus provides reliable, non-intrusive measurements of multiphase flow parameters, improving the accuracy of liquid and gas volume determinations and watercut measurements, while reducing the need for multiple measurement points and enhancing the reliability of flow characterization.
Implementation Method 1
Transducers transmit and receive high-frequency ultrasonic waves through the water
Implementation Method 2
measuring acoustic and/or dynamic pressures
Implementation Method 3
determine the speed of sound propagating through the process flow
Data Source
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AI summary
An apparatus is provided that determines a characteristic of a multiphase fluid, such as an aerated oil and water fluid, flowing within a pipe. The apparatus includes a fluid flow meter, a water cut meter, and a density meter, wherein the density meter determines the density of the fluid flow to determine the gas volume (or void) fraction of the multiphase fluid flow. The output signal of each of the meters is provided to a multiphase flow model to provide a plurality of multiphase parameters, such as phase fraction, volumetric flow, mass flow of each of the phases of the multiphase mixture, optimized for various flow conditions. Each of the meters may be secured to the outer surface of the pipe using various means, such a clamping means.