ISO/TR TECHNICAL REPORT 12748 First edition 2015-10-15 Natural Gas Wet gas flow measurement in natural gas operations Gaz naturel - Mesurage du débit de gaz humide dans les opérations de gaz naturel Reference number IS0/TR 12748:2015(E) ISO @IS02015 IS0/TR 12748:2015(E) COPYRIGHT PROTECTED DOCUMENT @ IS0 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +4122 749 09 47 copyright@iso.org www.iso.org @ IS0 2015 - All rights reserved IS0/TR 12748:2015(E) Contents Page Foreword ..vi Introduction. ..vii 1 Scope. ..1 2 Terms and Definitions ..1 3 Symbols. .10 4 Objectives of wet gas flow measurement ..13 4.1 Common production scenarios. .14 4.2 Production allocation. .15 4.3 Flow assurance aspects ..16 4.4 WGFM considerations ..16 4.5 Reliability in remote WGFM installations ..16 Flow regimes .17 5.1 Horizontal wet gas flow regimes ..17 5.1.1 Stratifiedflow .18 5.1.2 Slug flow. .18 5.1.3 Annular mist flow ..18 5.2 Vertical up wet gas flow regimes ..18 5.2.1 Churn flow .18 5.2.2 Annular mist flow .19 5.3 Vertical down wet gas flow regimes .19 5.4 Inclinedflow .19 5.5 Examples of wet gas flow regimes .19 5.6 Flow regime maps... 20 5.7 Different wet gas flow parameters. 21 5.8 Water in wet gas flow 21 6 Wet gas flow metering principles. .22 6.1 General. .22 6.2 In-Line wet gas flow meters. 23 6.2.1 Single-phase gas flow meter with correction factor .23 6.2.2 Two-phase wet gas flow meter. .24 6.2.3 Multiphase wet gas flow meter .24 6.3 Single-phase gas differential pressure meters with wet gas flow. 24 6.3.1 DP Meter design influence on wet gas over-reading .25 6.3.2 Lockhart-Martinelli parameter influence on DP meter wet gas flow over-reading. ..25 6.3.3 Gas to liquid density ratio influence on DP meter wet gas flow over-reading. ...25. 6.3.4 Gas densiometric Froude number influence on DP meter wet gas flow over-reading. .26 6.3.5 DP meter orientation influence on DP meter wet gas flow over-reading .26 6.3.6 Influence of β on DP meter wet gas flow over-reading. .28 6.3.7 Fluid property influence on DP meter wet gas flow over-reading 28 6.3.8 Meter size/diameter influence on DP meter wet gas flow over-reading 28 6.3.9 Applying DP meter wet gas flow correlations. 28 6.4 General discussion on DP meter wet gas correlations. 29 6.4.1 Wet gas flow performance characterization vs. published wet gas correlations..29 6.4.2 Horizontally-installed orifice plate meter. 29 6.4.3 Horizontally-installed Venturi meter. 31 6.4.4 Horizontally-installedconemeter ..32 6.5 Generic two-phase wet gas meter designs. ..33 6.5.1 Multiple single-phase meters in series. ..33 6.5.2 Differential pressure meter classical DP/permanent pressure loss wet gas meters.. .35 sn 2 s1dardizan rights reserved iii