ISO 18871:2015

INTERNATIONAL ISO
STANDARD 18871
First edition
2015-09-15
Method of determining coalbed
methane content
Méthode de dosage de la teneur en méthane de houille
Reference number
©
ISO 2015
© ISO 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 +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2015 – All rights reserved

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 . 6
3.13 Gas analyser . 6
4 Sample collection . 7
4.1 Preparation of sampling . 7
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. 8
4.3.2 Core samples . 8
4.3.3 Cutting samples . 8
4.4 Coal lump samples . 8
4.4.1 General. 8
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
6.4.7 Calculation of adsorption time .17
6.5 Numerical accuracy requirements .17
7 Measurement report .17
8 Quality commentaries .17
8.1 Quality commentary of sample collection .17
8.1.1 Situations should be noted on the record .17
8.2 Quality commentary on measuring operation .18
8.3 Conclusion of quality commentary .18
8.3.1 Qualified samples .18
8.3.2 Reference samples .18
8.3.3 Discard .18
Annex A (normative) Raw data of gas natural desorption .19
Annex B (normative) Lost gas original records table.21
Annex C (normative) Lost gas volume calculation of Sample XX (direct method) .22
Annex D (normative) Cumulative gas desorption curve of sample XX .23
Annex E (normative) Measurement results table of CBM content .24
Annex F (normative) Sampling form for in-seam drilling .25
Annex G (normative) Sampling form for core drilling .26
Annex H (normative) Laboratory test form.27
Annex I (normative) Short report .28
Bibliography .29
iv © ISO 2015 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO mem
...