-
Non-Intrusive Ultrasonic Gas Flow Meter Testing
• Michael Romer, ExxonMobil Upstream Research Company
• Tony Hord and Mike Johnson, ExxonMobil Production Company
• Izzy Rivera and Mike Kuvent, Flexim Americas Corporation
• Ron McCarthy and Bill Vaughan, Siemens Industry, Inc.
• Edward Beeloo and Craig Watterson, Expro Meters, Inc.
• Terry Grimley and Michael Robertson, Southwest Research Institute
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 1
37th Gas-Lift Workshop Houston, Texas, USA February 3 – 7, 2014
-
Outline
• Introduction
• Background
• Metering Technologies
• Flow Loop Facility
• Equipment Setup
• Results
• Challenges/Positives
• Conclusions and Future Plans
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 2
-
Introduction
• Does your asset have gas-lift (GL) gas metering?
– Can you measure injection for individual wells?
– Are the meters calibrated on schedule and correctly?
– Do you trust your metering system?
• What could you do if you were able to reliably meter
GL injection rates on each well?
– Individual well injection optimization
– Field-wide injection gas allocation & optimization
– Troubleshooting
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 3
-
Background
• In 2011, ExxonMobil piloted an ultrasonic (UT), clamp-on gas flow meter for measurement of injection gas
• Southwest Research flow loop and field testing showed potential for GL applications
• This spurred interest in other UT gas metering technologies
• A follow-up testing program was initiated in 2013 to validate other commercial UT meters for GL gas injection
• Priorities for metering solutions
– Non-intrusive
– Applicable to GL injection lines
– Portable if possible
– Relatively accurate (within 10%)
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 4
-
Metering Tech. – Meters F and S
• Transit-time principle
– Signal in the direction of flow travels faster than the signal against the flow direction
– The difference in transit time is a measure of the flow velocity
– Challenge: Diesel’s acoustic impedance is 372 times methane’s at 68°F, 150psi; methane’s received signal is .26% of diesel’s
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 5
Transit Time Difference, Δt Path of Ultrasonic Signal
© Copyright Flexim 2012 © Copyright Flexim 2012
-
Metering Tech. – Meters F and S
• Challenges of small diameter, thick pipe
– Low acoustic impedance means lower signal-noise ratio
– Noise signal = pipe wall signal from transmit receiver
– Thicker pipe has more noise; noise can arrive closer in time to measurement signal by going around small pipe
• Dampening materials help reduce noise
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 6
-
Metering Tech. – Meters F and S
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 7
• Transducer types
– Lamb Wave
• Frequency matched to the pipe wall thickness to
resonate the wall and create a wide beam
• Increase efficiency of sound transmission in gas
– Shear Wave
• Not matched to pipe wall; less uncertainty of sound
propagation time in the wall
• Single transducer can operate over wider range of
pipe sizes
-
Metering Tech. – Meters F and S
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 8
Lamb Wave principle
Pipe wall resonance
-
Metering Tech. – Meter E
• Sonar array processing for volumetric flow
– Directly measures velocity of coherent vortical
structures
• Vortical structures – turbulence of pipe wall shearing
• Coherent – maintain shape for 20-40 pipe diameters
• Direct – Gas composition is not required for
measurement – independent of acoustic impedance
– Independent of process pressure and pipe schedule
– Passive, strain-based and active, pulsed-array sonar
tools available
• Active sonar used in these tests
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 9
-
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 10
U/l3
1/l3
l2 U/l2
l3 U/l3
1/l1
U/l1
1/l2
U/l2
Wave Number
Fre
qu
ency
Temporal / Spatial Decomposition K-w plot
l1 U/l1
Frequency
Each spatial wavelength has a discrete temporal frequency ( f= U/ l )
Slope of Ridge Determines Flow Velocity
Metering Tech. – Meter E
-
Metering Tech. – Meter E
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 11
Passive, Strain-Based Sonar Active, Pulsed-Array Sonar
Sonar Algorithms Identify Ridge
Slope yields flow rate
6 inch Sonar Meter Perfromance
0
5
10
15
20
25
30
35
0 5 10 15 20 25 30 35
Reference Velocity, fps
Measu
red
Velo
city, f
ps
Slope of Ridge Determines Flow rate
Slope of
Convective Ridge:
27 fps
Slope of
Convective Ridge:
5 fps
Slope of
Convective Ridge:
17 fps
6 inch Sonar Meter Perfromance
0
5
10
15
20
25
30
35
0 5 10 15 20 25 30 35
Reference Velocity, fps
Measu
red
Velo
city, f
ps
Slope of Ridge Determines Flow rate
Slope of
Convective Ridge:
27 fps
Slope of
Convective Ridge:
27 fps
Slope of
Convective Ridge:
5 fps
Slope of
Convective Ridge:
5 fps
Slope of
Convective Ridge:
17 fps
Slope of
Convective Ridge:
17 fps
Slope of
Convective Ridge:
17 fps
-
Parameter Value(s) EM Test Value(s) Controllability Accuracy
170 MMscfd 0.4 - 4.3 MMscfd
1380 Acfm 6.3 - 43.8 Acfm
Pressure Range 165 - 1100 psig 600 - 1000 psig 1.0 psi 0.015% of value
Pipe Diameter Range 2 - 20 in. 3/4 - 2 in. - -
MRF HPL Operational Capabilities
Maximum Flow Rate 1.0 % of rate 0.1 - 0.25 % of rate
Flow Loop Facility
• Testing was performed at the Southwest Research Institute Metering Research Facility (MRF) High Pressure Loop (HPL)
– The HPL is a closed, recirculating flow loop; discrete gas rates are provided by a combination of critical flow nozzles and pressure is changed by adding/removing gas from the flow loop
– Meters being tested are benchmarked against calibrated critical flow nozzles; test data is recorded and can be analyzed on-line
– Sales-quality natural gas was used for the tests
• Flowmeter test was a low-rate, high-pressure HPL application
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 12
-
Flow Loop Facility – Test Matrix
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 13
Schedule
ID (in.)
Wall (in.) 600 1000
L5 6.3 370 615
L10 12.5 735 1225
L5+L10 18.8 1105 1840
L20 25.0 1470 2450
L5+L10+L20 43.8 2575 4290
Nozzle Acfm Velocity (ft/s) Mscfd
36 47
104
20 27 34 43 83 115 139
15 20 26 32 63 86
35
10 13 17 21 42 58 69
5 7 9 11 21 29
Pressure (psi)
0.218 0.344 0.200 0.281 0.179 0.250 0.154
80S
1.939 1.689 1.5 1.338 0.957 0.815 0.742
2 in. 1-1/2 in. 1-in. 3/4 in.
80 160 80 160 80 160Schedule
ID (in.)
Wall (in.) 600 1000
L5 6.3 370 615
L10 12.5 735 1225
L5+L10 18.8 1105 1840
L20 25.0 1470 2450
L5+L10+L20 43.8 2575 4290
Nozzle Acfm Velocity (ft/s) Mscfd
36 47
104
20 27 34 43 83 115 139
15 20 26 32 63 86
35
10 13 17 21 42 58 69
5 7 9 11 21 29
Pressure (psi)
0.218 0.344 0.200 0.281 0.179 0.250 0.154
80S
1.939 1.689 1.5 1.338 0.957 0.815 0.742
80 160 80 160 80 160
2-in. 1-1/2 in. 1 in. 3/4 in.
• Although wall thicknesses within
range for Lamb transducers,
corresponding pipe ID
recommendations were not
• Minimum pressure requirement
of ~150psi met for transducers
Accuracy
Meter Min. Max. (%)* Min. Max.
F 115 1-3 0.020 0.910
S 100 1-2 0.080 1.250
E 10 90 2
Calibrated
Velocity (ft/s) Wall Thickness (in.)
Lamb Transducer
* - Calibrated accuracies not expected for
measurements outside of calibrated conditions
-
Equipment Setup
• Two 15-ft spools of different pipe sizes were
tested simultaneously
– Larger ID pipe positioned upstream to limit
pressure loss and turbulence downstream
• Meters installed side-by-side on each spool
– Still allowed > 10ODs of space between meters
• All meters tested simultaneously
– Waveforms checked to ensure crosstalk not an
issue; cycled operational meter to verify
• Pressures and flow rates were iterated
– Temp. and pressure recorded near the spools
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 14
-
Equipment Setup – All Meters
Meter F Meter E Meter S
2 in. S80
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 15
• Portable or
Permanent
• ½ in. pipe and up
• Permanent or
Test Service
• 2 in. pipe and up
• Transportable or
Permanent
• ½ in. pipe and up (application dependent)
-
Equipment Setup – Meter F
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 16
1.5 in. S80
1.5 in. S160
1.5 in. S80
Acoustic Couplant
Dampening Material
Meter
Transducers
-
Equipment Setup – Meter S
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 17
1 in. S160
Meter
Transducers
.75 in. S80S
2 in. S80
Dampening Material
-
Equipment Setup – Meter E
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 18
Dampening Material
Sensor Head
Transmitter
Slope Determination
2 in. S80
-
Pipe (in.) Sched 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
80
160
80
160
80
160
0.75 80S
2
1.5
1
Velocity (ft/s)
Results – Meter F
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 19
600 psi 1000 psi Error: 0-4% 4-8% 8-12% No Measurement
Outside Meter’s Spec
-
Pipe (in.) Sched 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
80
160
80
160
80
160
0.75 80S
2
1.5
1
Velocity (ft/s)
Results – Meter S
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 20
600 psi 1000 psi Error: 0-4% 4-8% 8-12% No Measurement
-
Pipe (in.) Sched 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
80
160
80
160
80
160
0.75 80S
2
1.5
1
Velocity (ft/s)
Results – Meter E
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 21
600 psi 1000 psi Error: 0-4% 4-8% 8-12% No Measurement
-
Signal Quality Challenges
• Preparation of measurement location and installation of
components are key to success
– Smoothing, dampening material, and acoustic couplant
– Pipe ID quality will also affect accuracy
• In some applications it can be difficult to capture a quality signal
– Multiple hardware/electronic options available for finding a solution (particularly
with transit-time technologies); experience will guide usage
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 22
.75
in
. S
80S
2 in
. S
160
2 in
. S
80
-
Data Analysis Positives
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 23
• “All-or-Nothing” Data Collection
– If adequate signal quality cannot be achieved, you will not get data
• Transducer Spacing Forgiveness
– Able to experiment with transducer locations to optimize signal strength before securing both in place
– Actual spacing then input in meter
• Logging Capability
– Metered data can be exported to spreadsheet format and edited
– Initial input parameters can be determined and modified if necessary
-
Conclusions and Future Plans
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 24
• Non-intrusive UT technologies were successfully applied to GL gas measurement at the MRF
– Challenging pipe sizes/conditions and pressures
– All meters able to measure flow on all pipe sizes
– Better than 10% accuracy
• Training & experience are key components to measurement success
• Future Plans
– Continue and expand testing during GL optimization visits
– Incorporate with other GL diagnostic methods
– Investigate permanent technologies for expansion or retrofitting of GL metering
-
Questions?
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 25
37th Gas-Lift Workshop Houston, Texas, USA February 3 – 7, 2014
-
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 26
Copyright
Rights to this presentation are owned by the company(ies) and/or author(s) listed on the title page. By submitting this presentation to the Gas-Lift Workshop, they grant to the Workshop, the Artificial Lift Research and Development Council (ALRDC), and the American Society of Mechanical Engineers (ASME), rights to:
– Display the presentation at the Workshop.
– Place it on the www.alrdc.com web site, with access to the site to be as directed by the Workshop Steering Committee.
– Place it on a CD for distribution and/or sale as directed by the Workshop Steering Committee.
Other uses of this presentation are prohibited without the expressed written permission of the company(ies) and/or author(s) who own it and the Workshop Steering Committee.
-
Feb. 3 - 7, 2014 2014 Gas-Lift Workshop 27
Disclaimer
The following disclaimer shall be included as the last page of a Technical Presentation or Continuing Education Course. A similar disclaimer is included on the front page of the Gas-Lift Workshop Web Site.
The Artificial Lift Research and Development Council and its officers and trustees, and the Gas-Lift Workshop Steering Committee members, and their supporting organizations and companies (here-in-after referred to as the Sponsoring Organizations), and the author(s) of this Technical Presentation or Continuing Education Training Course and their company(ies), provide this presentation and/or training material at the Gas-Lift Workshop "as is" without any warranty of any kind, express or implied, as to the accuracy of the information or the products or services referred to by any presenter (in so far as such warranties may be excluded under any relevant law) and these members and their companies will not be liable for unlawful actions and any losses or damage that may result from use of any presentation as a consequence of any inaccuracies in, or any omission from, the information which therein may be contained.
The views, opinions, and conclusions expressed in these presentations and/or training materials are those of the author and not necessarily those of the Sponsoring Organizations. The author is solely responsible for the content of the materials.
The Sponsoring Organizations cannot and do not warrant the accuracy of these documents beyond the source documents, although we do make every attempt to work from authoritative sources. The Sponsoring Organizations provide these presentations and/or training materials as a service. The Sponsoring Organizations make no representations or warranties, express or implied, with respect to the presentations and/or training materials, or any part thereof, including any warrantees of title, non-infringement of copyright or patent rights of others, merchantability, or fitness or suitability for any purpose.