Coaxial Probe Array for High Salinity Water Cut Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flow meters fail to accurately measure water cut and salinity levels in multiphase mixtures with high salinity concentrations, leading to inaccuracy in well production optimization due to salinity-induced conductivity issues.
Innovation Solution
A high-frequency coaxial probe array operating at dual frequencies to minimize conductivity loss, with a processor that determines multiphase flow presence and measures water cut and salinity across a cross-sectional area of a production conduit, using a single set of driver electronics and performing frequency sweeps to account for systematic variance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If capacitance-based sensors are used to measure water cut, then measurement is feasible at low salinity, but measurement accuracy deteriorates at high salinity levels due to conductivity interference
Solution Approach 1:
The patent changes the measurement parameter from low-frequency capacitance to high-frequency dielectric measurement (above 1 MHz). This frequency parameter change allows the system to measure water cut in high salinity environments because the high frequency signal penetrates the conductive brine without being blocked by ionic conduction, thus resolving the contradiction between measurement accuracy and salinity interference
Solution Approach 2:
The patent replaces the conventional capacitance-based electrical measurement system with a high-frequency electromagnetic wave measurement system. By substituting the measurement mechanism to use electromagnetic waves instead of low-frequency electrical signals, the system can overcome the conductivity barrier imposed by high salinity and achieve accurate water cut measurement
2Measurement precision
If conventional single-frequency probes are used, then device complexity is low, but measurement accuracy deteriorates due to inability to account for frequency-dependent permittivity variations
Solution Approach 1:
The patent segments the measurement process into multiple frequency components by using a probe array that operates at multiple frequencies. This segmentation allows the system to capture frequency-dependent permittivity variations and selectively use the optimal frequency range for different salinity conditions, improving measurement accuracy despite increased device complexity
Solution Approach 2:
The patent creates a multi-functional probe array that can operate across a broad frequency spectrum (from kHz to GHz ranges). This universal probe design can adapt to different measurement conditions (freshwater, seawater, brine) by selecting appropriate frequency ranges, thereby achieving high measurement precision across diverse applications while managing device complexity through integrated electronics
3Measurement precision
If high-frequency operation is used to minimize conductivity loss, then water cut measurement accuracy improves, but device complexity increases due to specialized electronics requirements
Solution Approach 1:
The patent merges multiple probe elements operating at different frequencies into a single integrated probe array system with shared electronics. By combining the probe elements and utilizing multiplexed signal processing, the system achieves high-frequency measurement capability without proportionally increasing device complexity, as the driver electronics can serve multiple probe elements through time-division or frequency-division multiplexing
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 solution provides accurate real-time measurements of water cut and salinity in multiphase mixtures with high salinity levels, enhancing well production optimization by minimizing salinity-induced errors and optimizing area coverage and dynamic range.
Implementation Method 1
the measured complex reflection coefficient (i.e., ratio of reflected signal to the incident signal) is dependent on the aperture impedance (i.e., complex permittivity) of a sample material terminating the probe
Implementation Method 2
Capacitance is observed to increase between a pair of electrodes as the amount of water between the electrodes increases
Implementation Method 3
operating above a relaxation frequency of the brine water, and thus minimizing a conductivity loss relative to a capacitance
Data Source
AI summary
Disclosed is a flow meter and method for measuring water cut and salinity of a multiphase mixture. The water-cut meter includes a conduit configured to receive the multiphase mixture, and a probe array configured to measure a cross-sectional area of the conduit. The probe array includes a plurality of coaxial probes connected in parallel. Optionally, the probe array is configured to operate at a single high frequency, for example, 1 to 3 GHz, to minimize conductivity loss relative to capacitance. The flow meter further includes a processor configured to transmit a signal to the probe array and to receive a reflected signal from the probe array using a single channel. The processor is further configured to calculate the water cut and the salinity of the multiphase mixture based on a single complex permittivity of the multiphase mixture calculated from the received reflected signal.