Multiphase Flow Water Conductivity Measurement via Phase Difference
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Solution Overview
Problem
Existing methods for measuring the complex dielectric constant of multiphase mixtures in pipes are limited by inaccurate power and loss measurements, which are affected by impedance mismatches and standing waves, making it difficult to determine water conductivity and volume fraction accurately, especially in flowing hydrocarbon mixtures with varying salinity.
Innovation Solution
The method measures the complex dielectric constant by performing differential phase measurements at multiple frequencies between receiving antennas located at different distances from a transmitting antenna, allowing for accurate determination of real and imaginary dielectric constants without relying on power or loss measurements, thus reducing the impact of measurement distortions and scatter loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If power and loss measurements are used to determine the complex dielectric constant, then the measurement can be performed, but the measurement accuracy is reduced due to impedance mismatches and standing waves
Solution Approach 1:
The patent replaces power and loss measurements with phase difference measurements between receiving antennas. This substitution eliminates the impact of impedance mismatches and standing waves that plague traditional power-based methods, as phase measurements are inherently more robust to these artifacts. The system measures the phase difference of electromagnetic waves at multiple frequencies to determine the complex dielectric constant with high accuracy.
Solution Approach 2:
The patent measures the phase difference at multiple different frequencies (at least two frequencies in the range between 10 MHz and 10 GHz). By changing the frequency parameter and measuring phase differences across multiple frequencies, the system can accurately determine both the real and imaginary parts of the complex dielectric constant, overcoming the limitations of single-frequency power measurements.
2Measurement precision
If traditional measurement methods are used, then the measurement system is simpler, but the measurement is affected by scatter loss from droplets and bubbles
Solution Approach 1:
The patent substitutes power-based measurements with phase-based measurements. Phase difference measurements between receiving antennas are not affected by scatter loss from droplets and bubbles in the multiphase mixture, as the phase information is preserved through the scattering medium. This allows accurate measurement of the complex dielectric constant even in challenging multiphase flow conditions.
3Measurement precision
If power measurements are used, then the measurement can be performed, but impedance mismatches and standing waves introduce measurement errors
Solution Approach 1:
The patent replaces power measurements with phase difference measurements between receiving antennas located at different distances from the transmitting antenna. This substitution eliminates the harmful effects of impedance mismatches and standing waves, as phase measurements are inherently more robust to these artifacts. The phase difference method provides accurate determination of the complex dielectric constant without the measurement errors that plague traditional power-based approaches.
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
This approach provides highly accurate and repeatable measurements of water conductivity and volume fraction, unaffected by impedance mismatches and droplet/bubble size variations, enabling reliable measurements in multiphase flows with changing salinity.
Implementation Method 1
measuring the wave phase constant β of a plane electromagnetic wave propagating near the inside wall of the pipe
Implementation Method 2
The complex dielectric constant is determined by measuring the wave phase constant β of a plane electromagnetic wave propagating near the inside wall of the pipe
Data Source
AI summary
A method for determining the water conductivity and water volume fraction of a multi-component mixture of water and at least one additional liquid or gas in a pipe, the method comprising the following steps: a. electromagnetic phase measurements at least two measurement frequencies are performed between two receiving antennas located at different distances from a sending antenna, b. based on empirically determined constant(s) and the above measurements, the real and imaginary dielectric constants are determined, c. the temperature and pressure are determined d. based on the knowledge of the real and imaginary dielectric constants of the components of the fluid mixture and the result from the above steps a-c, the conductivity of the water and/or the volume fraction of water are determined. An apparatus for performing the method is also disclosed.