Resonant Cavity Multiphase Flow Meter Saline Water Interference
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Solution Overview
Problem
Existing methods for determining individual phase fractions in multiphase flows, particularly in hydrocarbon wells, face challenges in accurately measuring water fractions in gas/water or gas/condensate/water streams, especially when saline water is present, due to interference with electromagnetic resonance modes.
Innovation Solution
A resonant cavity-based method and apparatus that applies electromagnetic energy over a range of frequencies and uses resonance-mode altering structures within a non-conducting material to suppress or enhance specific resonance modes, allowing for clear discrimination of gas volume fractions and accurate phase fraction determination even with highly saline water.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electromagnetic resonance modes are used to measure phase fractions in multiphase flows, then measurement capability is provided, but measurement accuracy deteriorates when saline water is present due to interference with resonance modes
Solution Approach 1:
The patent converts the harmful effect of saline water interference into a beneficial selection criterion by identifying frequency windows where resonance modes are not affected by saline water. Instead of trying to eliminate the interference, the invention selects operating frequencies that naturally avoid the harmful interaction, thus converting the problem of saline water presence into a guide for frequency selection.
Solution Approach 2:
The patent changes the operating parameter (frequency) to avoid the harmful effects of saline water. By sweeping through a range of frequencies and identifying specific frequency windows where resonance modes are clear of saline water interference, the system dynamically selects optimal operating frequencies to maintain measurement accuracy despite the presence of conductive phases.
2Productivity
If continuous in-line real time measurements are implemented, then operational efficiency is improved, but measurement reliability deteriorates due to interference from conductive phases
Solution Approach 1:
The patent implements a dynamic frequency selection approach where the system continuously sweeps through a range of frequencies and adaptively identifies optimal frequency windows in real-time. This dynamic operation allows the system to maintain reliable measurements by continuously adjusting the operating frequency to avoid saline water interference, enabling continuous in-line measurement without sacrificing reliability.
Solution Approach 2:
The system uses feedback from the resonance mode analysis to continuously determine the quality of frequency windows and adjust operating parameters accordingly. By monitoring the resonance characteristics and identifying when frequency windows become obscured by saline water interference, the system can switch to alternative frequencies, maintaining continuous reliable measurement capability.
3Measurement precision
If resonance modes are used for phase fraction determination, then measurement capability is provided, but discrimination ability deteriorates when multiple phases including saline water are present
Solution Approach 1:
The patent segments the frequency spectrum into distinct frequency windows, each associated with specific resonance modes. By dividing the continuous frequency range into discrete usable segments and selecting only those frequency windows that are not obscured by saline water interference, the system maintains clear discrimination between different phase fractions while avoiding the harmful effects of conductive phases.
Solution Approach 2:
The patent uses frequency window analysis as an intermediary mechanism to separate the useful resonance mode information from the harmful saline water interference. By introducing the concept of frequency windows and using them as a filtering mechanism, the system can extract clear phase fraction information while excluding the obscuring effects of conductive phases.
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
Enables accurate and continuous in-line measurement of phase fractions by creating clear frequency windows for selected resonance modes, effectively distinguishing between gas, liquid hydrocarbon, and water phases, even in the presence of saline water, improving measurement accuracy and reliability.
Implementation Method 1
electromagnetic resonant sensors utilize the electromagnetic resonance principle to measure the complex permittivity of materials
Implementation Method 2
wavelengths and energy losses of electromagnetic waves are dependent on the complex permittivity of the dielectric material through which the waves are propagating
Implementation Method 3
suppressing at least one resonance mode within said cavity
Implementation Method 4
electromagnetic resonant sensors utilize the electromagnetic resonance principle to measure the complex permittivity of materials
Data Source
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AI summary
A multiphase meter for use in the quantification of the individual phase fractions of a multiphase flow has: a resonant cavity through which, in use, a multiphase fluid flows, a signal generator configured to apply electromagnetic energy at a range of frequencies to the cavity, and an enhancing and / or suppressing facility for enhancing and / or suppressing resonant modes of a signal produced resultant to the application of electromagnetic energy to the cavity.