BS ISO 18871:2015

Foreword
1 Scope
2 Terms and definitions
3 Apparatus
4 Sample collection
5 Measuring method and process
6 Data processing
7 Measurement report
8 Quality commentaries
Annex A (normative) - Raw data of gas natural desorption
Annex B (normative) - Lost gas original records table
Annex C (normative) - Lost gas volume calculation of
        Sample XX (direct method)
Annex D (normative) - Cumulative gas desorption curve
        of sample XX
Annex E (normative) - Measurement results table of
        CBM content
Annex F (normative) - Sampling form for in-seam drilling
Annex G (normative) - Sampling form for core drilling
Annex H (normative) - Laboratory test form
Annex I (normative) - Short report
Bibliography

Gives methodology for measuring coalbed methane content of coal core samples obtained by coring or sidewall coring during well drilling.

This International standard provides methodology for measuring coalbed methane content of coal core samples obtained by coring or sidewall coring during well drilling. This standard has to be also applied to drill cuttings samples, if the equipment for the determination of the coalbed methane content according to a respective national standard is not available. The selection of the most appropriate method shall consider the purpose of the test and the possibilities of sampling.

This International standard is applicable for the direct method of measuring coalbed methane content. It includes sample preparation, experimental procedures and calculation methods. Indirect methods of measuring gas content of coal (not included in this International standard) are generally based on either the gas sorption characteristics of coal under defined/specified pressure and temperature conditions.

This International standard includes three types of direct measuring methods: conventional desorption (slow desorption) of core samples, fast desorption of core samples, fast desorption of cuttings or lump samples. The difference among them lies in the time allowed for gas to desorb before final crushing and in sample size and shape.

This International standard is applicable for the determination of the methane content of coal during coal and coalbed methane exploration for the determination of free gas content of low rank coals is included.

Procedure of free gas content determination of low rank coals need to be defined.

All units used and referred to in this International standard are international standard units. Reference temperature is 0 °C (273,15 K) if not stated differently. Reference pressure is 0,1 MPa (1 bar) if not stated differently.

This International standard does not point out all the potential safety hazards associated with its use. The users are responsible for establishing appropriate safety measures and health practices when applying the procedures defined in this standard.