Microwave Doppler Flowmeter for Multiphase Wellbore Profiling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current downhole flowmeters are inadequate for accurately measuring and identifying the flow profile of various phases (oil, gas, and water) in hydrocarbon wells, particularly in harsh environments such as high temperatures and high pressures, and are not effective in deviated or horizontal wellbores.
Innovation Solution
A microwave doppler flowmeter using a dual antenna structure with a transmit antenna and a receive antenna, integrated with a microwave circuit, analog electronics, and digital processing module, capable of transmitting and receiving microwave signals at high frequencies (10-100 GHz) to measure fluid velocity and direction, and featuring a protective shell for durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional spinners are used to measure flow, then the device can detect fluid movement, but it cannot accurately identify and determine flow profile of various phases (oil, gas, water) in vertical, deviated or horizontal wellbores
Solution Approach 1:
The patent replaces the mechanical spinner system with an acoustic ultrasound system. The ultrasound transducers emit sound waves that interact with flowing fluids, and Doppler shifts in the reflected waves provide velocity measurements. This non-mechanical approach eliminates the limitations of spinners in measuring multiphase flow profiles in various well orientations, as acoustic waves can penetrate and measure different fluid phases (oil, gas, water) without mechanical contact.
Solution Approach 2:
The ultrasound flowmeter is designed with multiple transducers arranged to measure flow in different directions and orientations. The system can simultaneously measure axial flow, radial flow, and tangential flow components, making it universally applicable to vertical, deviated, and horizontal wellbores. This multi-functional capability allows accurate identification of flow profiles for various phases across different well orientations.
2Adaptability or versatility
If ultrasound flowmeter is used to measure liquid flow, then it can provide flow measurements, but it cannot measure gaseous flow or liquid-gas mixtures
Solution Approach 1:
The patent employs acoustic wave propagation and Doppler effect principles to detect fluid motion. Ultrasound waves can travel through gas, liquid, and multiphase mixtures, and the Doppler shift in frequency provides velocity information regardless of the fluid phase. This acoustic-based measurement mechanism overcomes the limitation of conventional ultrasound flowmeters that were designed only for liquid flow, enabling accurate measurement of gaseous flow and liquid-gas mixtures.
Solution Approach 2:
The system measures flow by detecting changes in acoustic wave parameters (frequency shift due to Doppler effect, attenuation, travel time) as waves interact with moving fluid phases. By analyzing these parameter changes, the flowmeter can distinguish between different fluid phases and accurately measure their velocities, even in complex multiphase conditions including gas and liquid-gas mixtures.
3Reliability
If downhole tools are deployed in harsh environments (high temperature up to 200°C, high pressure up to 2000 bars, corrosive fluid), then measurements can be obtained, but the tools face reliability challenges
Solution Approach 1:
The patent employs a protective housing or shell that encloses the ultrasound transducers and electronics, providing mechanical protection against high pressure and corrosive fluids. This protective barrier allows the tool to operate reliably in harsh downhole environments (temperatures up to 200°C, pressures up to 2000 bars) while maintaining measurement capabilities.
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 microwave doppler flowmeter provides accurate and robust measurements of fluid velocity and direction without the need for in-situ calibration, is compact, and can operate in extreme conditions, allowing for precise flow profile imaging in hydrocarbon wells.
Implementation Method 1
a microwave circuit comprising an oscillator (18) coupled to the transmit antenna (16Tx) for causing said antenna to transmit microwave signals towards the multiphase fluid at a high frequency ranging from 10 to 100 GHz, a mixer (19) coupled to the receive antenna (16Rx) and to a filter (20) for generating an analog in-phase doppler signal depending on microwave signals returned from moving multiphase fluid
Data Source
AI summary
A flowmeter measures a fluid velocity and/or direction of a moving multiphase fluid within a hydrocarbon well. The flowmeter includes a microwave front end module comprising transmit and receive antennas and a microwave circuit. The transmit antenna transmits electromagnetic signals towards the fluid at a high frequency ranging from 10 to 100 GHz. The flowmeter includes an analog electronics module converting an analog doppler signal successively into an amplified analog doppler signal and a digital doppler signal. The flowmeter includes a digital processing module comprising a Fast Fourier Transform algorithm for processing the digital doppler signal into a Doppler frequency spectrum. The Doppler spectrum contains information indicative of the fluid velocity and/or direction. A protective shell protects the modules from multiphase fluid. The protective shell comprises a first part positioned over the antennas and being transparent to electromagnetic signals, and a second part being opaque to electromagnetic signals.