37 th Gas-Lift Workshop Houston, Texas, USA February 3 7, 2014

Transcription

1 37 th Gas-Lift Workshop Houston, Texas, USA February 3 7, 2014 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, Gas-Lift Workshop 1

2 Outline Introduction Background Metering Technologies Flow Loop Facility Equipment Setup Results Challenges/Positives Conclusions and Future Plans Feb. 3-7, Gas-Lift Workshop 2

3 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, Gas-Lift Workshop 3

4 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, Gas-Lift Workshop 4

5 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 Copyright Flexim 2012 Copyright Flexim 2012 Transit Time Difference, Δt Path of Ultrasonic Signal Feb. 3-7, Gas-Lift Workshop 5

6 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, Gas-Lift Workshop 6

7 Metering Tech. Meters F and S 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 Feb. 3-7, Gas-Lift Workshop 7

8 Metering Tech. Meters F and S Lamb Wave principle Pipe wall resonance Feb. 3-7, Gas-Lift Workshop 8

9 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 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, Gas-Lift Workshop 9

10 Frequency Metering Tech. Meter E Each spatial wavelength has a discrete temporal frequency ( f= U/ l ) Temporal / Spatial Decomposition K-w plot l 1 U/l 1 U/l 3 l 2 U/l 2 l 3 U/l 3 U/l 2 U/l 1 Slope of Ridge Determines Flow Velocity Frequency 1/l 1 1/l 2 1/l 3 Wave Number Feb. 3-7, Gas-Lift Workshop 10

11 Measured Velocity, fps Metering Tech. Meter E Sonar Algorithms Identify Ridge 6 inch Sonar Meter Perfromance Slope of Ridge Determines Flow rate Slope of Convective Ridge: 17 fps Slope of Convective Ridge: 5 fps Slope of Convective Ridge: 27 fps Slope yields flow rate Reference Velocity, fps Passive, Strain-Based Sonar Active, Pulsed-Array Sonar Feb. 3-7, Gas-Lift Workshop 11

12 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 MRF HPL Operational Capabilities Parameter Value(s) EM Test Value(s) Controllability Accuracy 170 MMscfd MMscfd Maximum Flow Rate 1.0 % of rate % of rate 1380 Acfm Acfm Pressure Range psig psig 1.0 psi 0.015% of value Pipe Diameter Range 2-20 in. 3/4-2 in. - - Feb. 3-7, Gas-Lift Workshop 12

13 Flow Loop Facility Test Matrix 2-in /2 in. 1-in. 1 3/4 in. Schedule S ID (in.) Pressure (psi) Wall (in.) L L L5+L L L5+L10+L Nozzle Acfm Velocity (ft/s) Mscfd Calibrated Velocity (ft/s) Accuracy Lamb Transducer Wall Thickness (in.) Meter Min. Max. (%)* Min. Max. F S E * - Calibrated accuracies not expected for measurements outside of calibrated conditions Although wall thicknesses within range for Lamb transducers, corresponding pipe ID recommendations were not Minimum pressure requirement of ~150psi met for transducers Feb. 3-7, Gas-Lift Workshop 13

14 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, Gas-Lift Workshop 14

15 Equipment Setup All Meters 2 in. S80 Meter F Meter E Meter S 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) Feb. 3-7, Gas-Lift Workshop 15

16 Equipment Setup Meter F 1.5 in. S80 Dampening Material 1.5 in. S80 Transducers 1.5 in. S160 Meter Acoustic Couplant Feb. 3-7, Gas-Lift Workshop 16

17 Equipment Setup Meter S 1 in. S in. S80S Transducers Meter 2 in. S80 Dampening Material Feb. 3-7, Gas-Lift Workshop 17

18 Equipment Setup Meter E Transmitter 2 in. S80 Sensor Head Dampening Material Slope Determination Feb. 3-7, Gas-Lift Workshop 18

19 Results Meter F Velocity (ft/s) Pipe (in.) Sched Outside Meter s Spec S 600 psi 1000 psi Error: 0-4% 4-8% 8-12% No Measurement Feb. 3-7, Gas-Lift Workshop 19

20 Results Meter S Velocity (ft/s) Pipe (in.) Sched S 600 psi 1000 psi Error: 0-4% 4-8% 8-12% No Measurement Feb. 3-7, Gas-Lift Workshop 20

21 Results Meter E Velocity (ft/s) Pipe (in.) Sched S 600 psi 1000 psi Error: 0-4% 4-8% 8-12% No Measurement Feb. 3-7, Gas-Lift Workshop 21

22 .75 in. S80S 2 in. S80 2 in. S160 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, Gas-Lift Workshop 22

23 Data Analysis Positives 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 Feb. 3-7, Gas-Lift Workshop 23

24 Conclusions and Future Plans 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 Feb. 3-7, Gas-Lift Workshop 24

25 37 th Gas-Lift Workshop Houston, Texas, USA February 3 7, 2014 Questions? Feb. 3-7, Gas-Lift Workshop 25

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 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, Gas-Lift Workshop 26

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-inafter 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, noninfringement of copyright or patent rights of others, merchantability, or fitness or suitability for any purpose. Feb. 3-7, Gas-Lift Workshop 27