Dynamic Venturi Flowmeter for Multiphase Wellbore Measurement
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Solution Overview
Problem
Selecting the optimal throat size for a Venturi flowmeter in wellbore applications is challenging due to varying Gas-Oil ratios (GOR) over time, leading to differential pressure issues.
Innovation Solution
A dynamic Venturi flowmeter with movable walls that adjust the orifice size in response to changing mass flow rates, ensuring accurate pressure measurements and flow rate determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed throat size is selected for the Venturi flowmeter, then the device structure is simple, but the measurement accuracy deteriorates when GOR changes over time
Solution Approach 1:
The patent applies the dynamics principle by replacing the fixed throat size with a movable wall that dynamically adjusts the orifice area in response to changing flow conditions. The movable wall responds to pressure differential changes caused by varying GOR, automatically optimizing the throat size for current flow conditions and maintaining measurement accuracy despite changes in fluid composition over time.
2Adaptability or versatility
If the throat size is made smaller to handle high GOR fluids, then high GOR measurement capability is improved, but low GOR measurement accuracy deteriorates due to excessive differential pressure
Solution Approach 1:
The movable wall dynamically adjusts the orifice size based on real-time flow conditions. When high GOR fluids are present, the wall moves to create a smaller orifice area, increasing differential pressure for accurate measurement. When low GOR fluids are present, the wall opens the orifice wider, reducing differential pressure to within the operational range, thus maintaining measurement accuracy across varying GOR conditions.
Solution Approach 2:
The patent changes the geometric parameter of the orifice area dynamically. The movable wall alters the throat cross-sectional area in response to flow conditions, transitioning between different orifice sizes. This parameter change allows the same device to optimize its measurement characteristics for both high and low GOR fluids without requiring multiple fixed-configuration meters.
3Measurement precision
If the throat size is made larger to handle low GOR fluids, then low GOR measurement accuracy is improved, but high GOR measurement capability deteriorates due to insufficient differential pressure
Solution Approach 1:
The movable wall dynamically adjusts the orifice size based on real-time flow conditions. When low GOR fluids are present, the wall opens the orifice wider to reduce differential pressure and improve measurement accuracy. When high GOR fluids are present, the wall closes the orifice to increase differential pressure, ensuring both measurement types can be accurately captured within the operational envelope.
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 dynamic Venturi flowmeter effectively adapts to varying flow conditions, providing accurate and reliable measurements of multiphase flow from wellbores, regardless of changing GOR.
Implementation Method 1
One or more movable walls are coupled within the outer pipe and circumscribing a conical flow path defining an orifice at a downstream end thereof for constricting the wellbore fluid to a restricted state. The movable walls are responsive to increasing mass flow rates of the wellbore fluid to expand the orifice and responsive to decreasing mass flow rates of the wellbore fluid to diminish the orifice.
Implementation Method 2
At least one sensor is operable to detect a parameter indicative of the pressures of the wellbore fluid in the unrestricted and restricted states.
Implementation Method 3
A converging throat is defined in the chamber that restricts flow and thereby increases a velocity of the flow through the chamber. One or more sensors measure a pressure difference between the restricted and unrestricted flow, from which a total mass rate of the flow may be determined.
Data Source
AI summary
A flowmeter includes an inlet for receiving a wellbore fluid therein, an outlet for discharging the wellbore fluid and a stationary outer pipe extending between the inlet and the outlet and exhibiting a first diameter for receiving the wellbore fluid in an unrestricted state. One or more movable walls are coupled within the outer pipe and circumscribe a conical flow path defining an orifice at a downstream end thereof for constricting the wellbore fluid to a restricted state. The movable walls responsive to increasing mass flow rates of the wellbore fluid to expand the orifice and responsive to decreasing mass flow rates of the wellbore fluid to diminish the orifice. At least one sensor is operable to detect a parameter indicative of the pressures of the wellbore fluid in the unrestricted and restricted states.