ISO INTERNATIONAL STANDARD 18871 First edition 2015-09-15 Method of determining coalbed methane content Methode de dosage de la teneur en methane de houille Reference number IS0 18871:2015(E) ISO @IS02015 IS0 18871:2015(E) COPYRIGHTPROTECTEDDOCUMENT @ 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 Copvriaht Inte IS0 18871:2015(E) Contents Page Foreword ..V 1 Scope ..1 2 Terms and definitions ..1 3 Apparatus. .3 3.1 Desorption canister .3 3.2 Metering device. .3 3.3 Thermostat. .5 3.4 Temperature measuring devices .5 3.5 Barometer .5 3.6 Electronic balance (top load) .5 3.7 Standard sieve. .5 3.8 Coal crusher .5 3.9 Hose. .6 3.10 Gas-sample bottles ..6 3.11 Padding. .6 3.12 Quick connector 3.13 Gas analyser. .6 4 Sample collection. .7 4.1 Preparation of sampling 4.1.1 General. 7 4.1.2 Desorption canister 7 4.1.3 Metering device. 7 4.1.4 Thermostat .7 4.2 Sampling principle.. .7 4.2.1 Sample quality .7 4.2.2 Sampling time .8 4.3 Sampling procedure. ..8 4.3.1 General. 4.3.2 Core samples ..8 4.3.3 Cutting samples ..8 4.4 Coal lump samples. ..8 4.4.1 General. 4.4.2 Parameters to record ..8 5 Measuring method and process. .9 5.1 Use of core samples.. ..9 5.1.1 Natural desorption .9 5.1.2 Measurement of residual gas. .10 5.1.3 Gas sampling, composition analysis and isotope analysis ..10 5.2 Use of cuttings samples or coal lump samples ..12 5.2.1 Q2 measurement. ..12 5.2.2 Q3 measurement. ..12 6 Data processing ..13 6.1 Conversion of the desorbed gas volume .13 6.2 Reporting of gas content. .13 6.3 Calculation of gas composition 13 6.4 Calculation of gas content .13 6.4.1 General. .13 6.4.2 Calculation of lost gas content (Q1) .13 6.4.3 Calculation of gas desorption content (Q2) .15 6.4.4 Calculation of residual gas content (Q3) .15 6.4.5 Calculation of free gas content. .16 6.4.6 Calculation of gas content.. ..16 isn aS1dardizan rights reserved iii