A CONTRIBUTION TO ECONOMIC UPSTREAM GAS METERING. Jörg Wenzel SICK AG European Flow Measurement Workshop March 2016, Noordwijk

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1 A CONTRIBUTION TO ECONOMIC UPSTREAM GAS METERING Jörg Wenzel SICK AG European Flow Measurement Workshop March 2016, Noordwijk

2 AGENDA Motivation Meter design and LP/HP test results Wet gas: Test results and diagnostics Field test findings Summary and Conclusions 2

3 MOTIVATION Challenging conditions in gas production: Varying flow rates Varying gas quality Saturated gas streams with entrained liquids Demand for meters that are: Robust for use in production environments Economic in a long-term perspective In fact: Meters for gas production applications are mainly covered by dp meters. 3

4 MOTIVATION What about Ultrasonic meters in gas production? USM are equally applicable: Robust, even for high LVF no wear Self-draining, self-recovering USM provide several advantages over dp meters: ( + ) Higher turn-down ratio ( + ) Reduced pressure drop ( + ) Virtually no maintenance ( + ) Valuable diagnostics data 4

5 MOTIVATION Test Separator Production Separator Main challenges: Class 1 or Class 2 accuracy Pressure on CapEx and OpEx Robustness and reliability March 2016 J. Wenzel European Flow Measurement Workshop Noordwijk 5

6 AGENDA Motivation Meter design and LP/HP test results Class 1 or Class 2 accuracy Wet gas: Test results and diagnostics Robustness and reliability Field test findings Pressure on CapEx and OpEx Summary and Conclusions 6

7 AGENDA Motivation Meter design and LP/HP test results Class 1 or Class 2 accuracy Wet gas: Test results and diagnostics Robustness and reliability Field test findings Pressure on CapEx and OpEx Summary and Conclusions 7

8 METER DESIGN Meeting Class 1 accuracy and CapEx expectations Dual-path meter Integrated inlet pipe High precision manufacturing process Class 1 performance without need for HP calibration 8

9 TEST RESULTS AS-FOUND RESULTS 7-POINT AMBIENT AIR FLOW TEST High repeateability High linearity Keeps Class 1 limits Close to limits below 100m³/h Stability relates to Re Worst case scenario Pressure = Linearity <0.5% spread in high Re 9

10 TEST RESULTS AS-FOUND RESULTS IN HIGH PRESSURE NATURAL GAS Class1 limits are kept No difference between 4 and 50 bar Internal Re & Geometry corr. Add. uncertainty <1/3 MPE Re relation verified No systematic bias Convergation to ~ ± 0.5% Total Meter uncertainty ± 1% achieved 10

11 AGENDA Motivation Meter design and LP/HP test results Wet gas: Test results and diagnostics Field test findings Summary and Conclusions 11

12 WET GAS TEST RESULTS 12

13 WET GAS TEST RESULTS LIQUID DETECTION stratified and non-stratified flow pattern region Fr g Fr g < 1,2 stratified Fr g > 1,2 non-stratified the low liquid loading side of multiphase flow GVF GVF > 95% the wet-gas envelop X LM X LM < 0,3 13

14 WET GAS TEST RESULTS RAMP-UP TESTS Stratified Flow Ramp-up test up to X LM =0.9 representing LVF=13.2% Uninterrupted meter readings Significant over-reading for high X LM Recovery of the meter 14

15 WET GAS DIAGNOSTICS LIQUID DETECTION Wet gas affects any meter accuracy But do I expect it to be wet? Algorithm using USM diagnostics to generate a warning when liquids are present that may have an impact on process quality or measurement accuracy 15

16 WET GAS TEST RESULTS LIQUID INDICATION Initial results of liquid detection diagnosis (blind test) Majority of test points with high overreading have been detected Improvement needed 16

17 WET GAS TEST RESULTS LIQUID INDICATION Unique test data allowed to improve liquid detection algorithm All test points affecting the meter performance are detected All green points are within ± 2.5% accuracy 17

18 AGENDA Motivation Meter design and LP/HP test results Wet gas: Test results and diagnostics Field test results Summary and Conclusions 18

19 FIELD TEST RESULTS THE VALUE OF HIGH TURN-DOWN Field test for 3 months in shale gas production Installation downstream two-phase separator in series with dp meter 19

20 FIELD TEST RESULTS THE VALUE OF HIGH TURN-DOWN 3 USM covers flow range of 2 6 orifice plate meter Orifice plate USM 3 Beta=0.5, dp<500 mbar VOG<30 m/s Beta=0.6, dp<625 mbar VOG<45 m/s 20

21 Average hourly flow rate [m³/h] FIELD TEST RESULTS THE VALUE OF HIGH TURN-DOWN Highly dynamic and unpredicteable flow rate within first 15 days Hourly average data from SCADA system Time [h] 21

22 Average hourly flow rate [m³/h] Meter out of range [%] FIELD TEST RESULTS THE VALUE OF HIGH TURN-DOWN SCADA reported out-of-range time of both flow meters before calculating average flow rate % % 60% % 20% 0 0% Time [h] Flow rate Orifice USM 22

23 FIELD TEST RESULTS THE VALUE OF HIGH TURN-DOWN During further test period, 3 different orifice plates have been used Gas passes the meters unregistered when out-of-range Accumulated 90 day differences: Orifice meter USM Difference In range reading (min) In range total flow volume (MCF) In range gas value (USD) $ $ $

24 FIELD TEST RESULTS THE VALUE OF DIAGNOSTIC Regular sampling is used to gain correct gas quality SOS changes with gas composition (p/t balanced) SOS from USM can be used as trigger for sampling intervals 01/26/2015: 1280 BTU, SOS Calc =SOS Meas =355 m/s 04/08/2015: 1335 BTU, SOS Calc =SOS Meas =345 m/s Price difference = 11 ct/mcf ~ $14,000 in 70 days 24

25 AGENDA Motivation Meter design and LP/HP test results Wet gas: Test results and diagnostics Field test results Summary and Conclusions 25

26 SUMMARY / CONCLUSIONS USM can be well applied in gas production applications Class 1 accuracy (dry gas) ensured without HP calibration USM provide reliable readings even in wet gas and comes with valuable liquid detection USM provide economic advantages in gas production by higher turn-down and lower operational costs USM diagnostics provide added-value for further cost-savings (e.g. condition-based maintenance and sampling) 26

27 MANY THANKS FOR YOUR ATTENTION. Jörg Wenzel Product Management SICK Flow Solutions