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Methodology for Liquid Ultrasonic Flow Measurement within the Laminar to Turbulent Transitional Zone Dave Seiler Daniel Measurement and Control March 25, 2014

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Heavy Oil Definition !! !!the API classifies heavy oil as crudes with a

gravity below 22.3° API !! !!although variously defined, the upper limit for

heavy oil is 22° API gravity with a minimum viscosity of 100 cp (centipoise).

!! Heavy oil deposits around the world share only one characteristic: they are challenging to produce.

!! The “easy” crude oil is becoming harder to find

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Traditional Measurement Technology – Displacement Meter

All Displacement Meters rely on a capillary seal for good performance

Dual Rotor

Measuring Chamber

Meter Housing

Rotor

Cam Inner Unit Housing

Static Liquid

Blade Path of Blades

Flowing Liquid

Sliding Vane

Bearings

Capillary Seal

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Reynolds Number Affect on Displacement Meter

Minimum “slippage”

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Alternative Technologies

Helical Turbine Meter

Coriolis Meter Ultrasonic Meter

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Ultrasonic Meters !! Industry acceptance of Liquid Ultrasonic is driving

technology growth !! Technology is well entrenched into custody

transfer type applications !! Manufacturers are continuing to invest and drive

for “ease of use” and improvements in measurement

!! Customers are applying the technology into more complex applications

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Transit Time USM – How It Works?

!! Measures transit times of ultrasonic pulses

!! Transducer locations placed for optimum measurement accuracy

!! Transducers act alternately as transmitter and receiver

Multipath Liquid USM

Multipath Liquid USM

4321

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1382.03618.03618.01382.0 vvvv

vwVn

iiiaverage

!+!+!+!=

="=

AVQ average !=where Q = flow rate A = cross sectional area of the

Meter bore

Flow

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Liquid Ultrasonic Meter High Viscosity Flow Measurement Challenge

•! Measurements are dependent on velocity profile •! Velocity profile is Reynolds number (Re) (i.e. flow regime)

dependent •! Turbulent: Re>5000 •! Laminar: Re<2000 •! Transitional 2000<Re<5000

•! Liquid ultrasonic flow meters perform the best in the turbulent regime

•! Measurement non-linearity increases rapidly as Re<104 in conventional flow measurement applications

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The Challenge !! Develop a transducer capable of transmitting a signal

through a high viscosity fluid

!! Accurately measure volume through all flow regimes including Transitional

Transducer Housing

Transducer Capsule

Transducer Retainer

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Objective

Develop a methodology to measure high viscosity fluid flow rate using liquid ultrasonic meters with high accuracy required for custody transfer applications

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Typical Meter Run – API 5.8

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Installations

Flow

Elbow Flow

Tee or Header

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Conventional Flow Measurement Error vs. Reynolds Number Curves

Turbulent Laminar Transition

Experimental Error

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Conventional Flow Measurement Error vs. Reynolds Number Curves

Turbulent Laminar Transition

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Conventional Flow Measurement Error Curves

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Conventional Flow Measurement Error Curves

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Potential Solutions

•! Correct meter error without changing the fluid flow velocity profile (electronic corrections in meter firmware)

•! Difficult to formulate algorithms across flow regimes and for different upstream piping configurations

•! Modify fluid flow velocity profile to one that can be accurately measured

•! Utilize special (custom) flow conditioners •! Employ a combination of both of the above for the entire

Reynolds number range

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Proposed Piping Solutions

CPA Plate

3D

With large upstream pipe Without large upstream pipe

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Flow Development with an Upstream Diffuser

-! Velocity Profile "! Average Velocity along path

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Flow Development with an Upstream Diffuser !! Re_1000_TRANS_VenturiC_3DHEAD_PORTS_

DivConv_POS_VelProfDev.avi !! Re_1985

TRANS_VenturiC_3DHEAD_PORTS_POS_VelProfDev.avi

!! Re_6150 Turb_VenturiC_3DHEAD_PORTS_POS_VelProfDev.avi

!! Re_6150_Turb_VenturiC_3DHEAD_PORTS_DivConv_POS_VelProfDev.avi

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!! High viscosity flow loop –! up to 1000cSt –! Temperature controlled –! 8” PD Master Meter –! 18” SVP

Daniel Test Loop - Houston

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Performance Results - 8” Liquid Ultrasonic Meter with Proposed Piping

!! SVP proves the master meter !! Master proves the Liquid USM !! Master Meter re-proven

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Performance Results - 8” Liquid Ultrasonic Meter with Proposed Piping

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Liquid Ultrasonic Flow Meter Performance for Different Viscous Fluids

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Performance of Different Size Meters

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Summary

•! CFD provided additional insight to improve liquid ultrasonic flow meter performance with Gaussian quadrature integration with Chebyshev’s polynomials of second kind

•! Flow conditioning has a significant effect on 4 path liquid ultrasonic meter performance in low Reynolds number regions

•! Employing the proposed piping solutions can achieve the accuracy required for custody transfer within laminar to turbulent transitional zone

•! Utilization of flow conditioning upstream of a reducer provided approximately 80% less pressure drop compared to conventional bore matched flow conditioning

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“People who say it cannot be done should not interrupt those

who are doing it."

– George Bernard Shaw