ISO 4657:2022

Assessment specification of coalbed methane resources

This document specifies the objectives, tasks, work processes, classification, report preparation and acceptance of coalbed methane (CBM) resource evaluation.

Spécifications d’évaluation des ressources en méthane de houille

General Information

• Status: Published
• Publication Date: 11-Jan-2022
• ICS: 73.020 - Mining and quarrying
• Technical Committee: ISO/TC 263 - Coalbed methane (CBM)
• Drafting Committee: ISO/TC 263 - Coalbed methane (CBM)
• Current Stage: 6060 - International Standard published
• Start Date: 12-Jan-2022
• Due Date: 25-Mar-2022
• Completion Date: 12-Jan-2022

Overview

ISO 4657:2022 - Assessment specification of coalbed methane resources - defines a standardized framework for evaluating coalbed methane (CBM) resource potential. Published in 2022, this international standard specifies objectives, tasks, work processes, classification rules, and report preparation and acceptance criteria for CBM resource evaluation. ISO 4657:2022 establishes consistent methods and documentation practices to support reliable resource estimates and to underpin subsequent reserves reporting and development planning.

Key topics and technical requirements

• Evaluation workflow: a structured sequence covering data collection and collation, geological condition analysis, evaluation method selection, input-parameter assignment, resource calculation, classification and conclusions.
• Data requirements:
  • Geophysical data (gravity, magnetic, seismic, electrical) to map faults, structure and coal seam depth.
  • Regional geological and hydrogeological datasets, coalfield reports and adjacent-area production data.
  • Drilling data: mud logging (cuttings, coring, gas logging), conventional and unconventional wireline logs (density, neutron, acoustic, NMR, imaging), and well testing.
  • Laboratory tests: core description, bulk density, macerals, proximate/elemental analyses, vitrinite reflectance, gas composition, gas content (per ISO 18871), and isothermal adsorption.
• Calculation method: the volumetric method is the prescribed approach when geological data are adequate; principles for parameter assignment (thickness, density, gas content, area) must be documented and justified.
• Parameter rules and cut-offs:
  • Effective (net) thickness determination and area-weighted averaging; seam cut-off for effective thickness set at 0.5 m (individual seams below this threshold are ignored after gangue deduction).
  • Coal density: use arithmetic average of laboratory-measured samples.
  • Gas content: laboratory measurement per ISO 18871 and conversion rules for reporting bases (dry ash-free, ash-free, air-dried).
• Resource boundaries: define gas-bearing area using geological and anthropogenic controls (faults, pinch-outs, erosion, gas-content cut-offs, weathering, spontaneous combustion, goaf) and mineral-right or geographic limits.
• Reporting: standardized content, figures and tables; Annex provides an example evaluation report outline.

Applications

• Preparing CBM resource assessments to inform exploration planning and feasibility studies.
• Supporting conversion of resource estimates into CBM reserves and economic appraisal.
• Guiding data acquisition programs (drilling, logging, lab tests) and quality requirements.
• Standardizing documentation for regulators, investors and project partners.

Who should use this standard

• Petroleum and coal geologists, reservoir and production engineers
• Energy companies and CBM developers
• Exploration and environmental consultants
• Regulators and resource auditors involved in CBM permitting and reporting

Related standards

• ISO 18871 - Method of determining coalbed methane content (normative reference cited by ISO 4657:2022)

Keywords: ISO 4657:2022, coalbed methane, CBM resource evaluation, volumetric method, gas content, wireline logging, laboratory test, resource classification, CBM reserves.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 4657
First edition
2022-01
Assessment specification of coalbed
methane resources
Spécifications d’évaluation des ressources en méthane de houille
Reference number
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
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CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General principles . 2
4.1 Objective. 2
4.2 Basic requirements . 2
5 CBM resource evaluation workflow .2
5.1 General . 2
5.2 Data collection and collation . 2
5.2.1 Geophysical data. 2
5.2.2 Regional geological data . 2
5.2.3 Drilling data . 3
5.2.4 Laboratory test data . 3
5.3 Geological conditions analysis . 3
5.3.1 Determination of exploration degree . 3
5.3.2 Geologic map compiling . 4
5.3.3 Comprehensive analysis . 4
5.4 CBM resource calculation . 4
5.4.1 General . 4
5.4.2 Principles for input parameters value assignment for volumetric method . 4
5.4.3 Volumetric method for CBM resources . 5
5.4.4 E valuation method for CBM reserves . 6
5.5 Resource classification . 7
6 Compilation of resource evaluation reports . 8
6.1 Report requirements. 8
6.2 Report text outline . 8
6.3 Figures . 8
6.4 Tables . 8
Annex A (informative) Example of a CBM resource evaluation report outline .9
Bibliography .10
iii
Foreword
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 263, Coalbed methane (CBM).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
INTERNATIONAL STANDARD ISO 4657:2022(E)
Assessment specification of coalbed methane resources
1 Scope
This document specifies the objectives, tasks, work processes, classification, report preparation and
acceptance of coalbed methane (CBM) resource evaluation.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 18871, Method of determining coalbed methane content
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
coalbed methane
CBM
methane-rich gas naturally occurring in coal seams (and surrounding rock) typically comprising of
80 % to 95 % methane with lower proportions of ethane, propane, nitrogen and carbon dioxide
Note 1 to entry: In common international use, this term refers to methane recovered from un-mined coal seams
using surface boreholes.
[SOURCE: ISO 18875:2015, 2.1]
3.2
CBM abundance
amount of hydrocarbons in unit area
[SOURCE: ISO 18875:2015, 2.28, modified — “resource” has been deleted from the term.]
3.3
CBM content
volume of hydrocarbon gas per unit mass of coal, usually expressed in cubic metre of gas per tonne of
coal under standard temperature and pressure (STP) conditions
3 3
Note 1 to entry: The unit is m /t or cm /g. STP conditions are 100 000 Pa and 0 °C (273,15 K).
[SOURCE: ISO 18875:2015, 2.5]
3.4
resource
quantities of petroleum, recoverable and unrecoverable, that are estimated to exist originally in
naturally occurring accumulations, discovered and undiscovered, plus those quantities already
produced
3.5
reserves
quantities of petroleum anticipated to be commercially recoverable by application of development
projects to known accumulations from a given date forward under defined conditions
4 General principles
4.1 Objective
The objective of the evaluation is to understand the distribution of CBM and the basic geological
characteristics of CBM reservoirs in the evaluation region, locate the CBM exploration targets, evaluate
the total amount, quality and certainty of CBM resources, lay a foundation for submitting a CBM
reserves report, and provide a basis for prospective planning of CBM exploration and development.
4.2 Basic requirements
4.2.1 The evaluation work shall be conducted and submitted independently.
4.2.2 The relevant data collected shall be reliable, representative and consistent. The data quality
shall meet the requirements of various professional specifications.
5 CBM resource evaluation workflow
5.1 General
The workflow of resource evaluation mainly includes data collection and collation, geological condition
analysis, evaluation method selection, input parameters value assignment, resource calculation, and
resource classification and conclusions.
5.2 Data collection and collation
5.2.1 Geophysical data
The interpretation results of gravitational, magnetic, electric and seismic data in the evaluation region
shall be fully used to analyse the characteristics of faults, stratum distribution and coal seam burial
depth, and to predict the control on CBM accumulation by faults, roof and floor conditions and the
variation trend of coalbed thickness.
5.2.2 Regional geological data
Regional geological data includes:
a) regional geographical data (including geographical location, topography, rivers, natural resources,
and major events such as earthquakes);
b) regional geological data and research achievements (including rocks, strata, structures, minerals,
crustal movement and development history);
c) hydrogeological survey data (including general status of groundwater resources; lithology and
distribution of aquifers; genesis, types, recharge and discharge conditions of groundwater;
distribution of water quality and quantity; division of hydrogeological units);
d) relevant information of extraction in the adjacent regions (including CBM resources, exploration
and development, dewatering and production, ground water extraction and gas production);
e) coalfield exploration reports and maps (including geological exploration reports compiled at
different exploration stages, final reports and maps);
f) coal mining data (including shaft development and mining design, mining roadway layout, shaft
reserves, production capacity and s
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