ISO TR 7262-2022 pdf download.Natural gas — Coalbed methane quality designation and the applicability of ISO/TC 193 current standards
5 Applicability of sampling standard
ISO 10715 provides concise guidelines for the collection, conditioning and handling of representative samples of processed natural gas streams. It also contains guidelines for sampling strategy, probe location and the handling and design of sampling equipment. According to ISO 10715, the factors affecting sampling representativeness include sampling material and equipment, sample containers,sampling method, heavy hydrocarbon condensate and flow characteristics of gas sources.
NOTE Specific CBM sampling standards exist at national level [5] .
CBM is a kind of unconventional natural gas, which falls into the category of natural gas. It is basically free of heavy hydrocarbon and organic sulfur compounds. The composition of CBM is simpler than that of natural gas.
Therefore, ISO 10715 is applicable to the direct and indirect sampling of CBM.
6 Applicability of test and calculation standard
6.1 General
This clause deals with the various parameters which may be referred to in a designation of the quality of CBM. The parameters actually selected will depend upon the purpose for which the designation is required and it is unlikely that all the parameters listed in this document will be used.
6.2 Gas composition
6.2.1 General CBM is composed primarily of methane and ethane with smaller amounts of propane, butane and of non-combustible gases, carbon dioxide and nitrogen, the approximate content of each component is shown in Table 1.
The relevant ISO/TC 193 test standards for major and minor components and trace constituents and whether these standards are applicable to CBM are shown in Table 2, 3 and 4. Limits are not given in this document, but limits on CBM components or properties are given in Chinese national standard GB/T 26569:2011 [26] and GB/T 26127:2010 [27] , Chinese energy industry standard NB/T 10035:2006, Australian standard AS 4564-2011 [28] , New Zealand Standard NZS 5442:2008 [29] (for more information, see Annex A and Bibliography).
6.2.2 Major components
Table 2 presents the main components of coalbed methane.
a) Methane
ISO 6974-4, ISO 6974-5, ISO 6974-6, and ISO 23978 are suitable for the determination of methane in the range of 75 % to 100 %, 34 % to 100 %, 40 % to 100 %, and 50 % to 100 %, respectively. Generally, the methane content in CBM is basically above 80 %, also above 50 % in some CBM with high nitrogen or oxygen content. There is no case in which methane content in CBM is lower than 34 %.
Therefore, ISO 6974-4, ISO 6974-5, ISO 6974-6 and ISO 23978 are able to meet and applicable to the determination of methane content in CBM. ISO 6974-1, ISO 6974-2, and ISO 6974-3 are also applicable to the determination of methane content in CBM.
b) Ethane
ISO 6974-4, ISO 6974-5, ISO 6974-6 and ISO 23978 are suitable for the determination of ethane in the range of 0,001 % to 10 %, 0,1 % to 23 %, 0,002 % to 15 %, and 0,02 % to 20 %, respectively. Generally, the ethane content in CBM is basically lower than 5 %, and in a few exceptions, not higher than 23 %. Therefore, ISO 6974-4, ISO 6974-5, ISO 6974-6 and ISO 23978 are able to meet and applicable to the determination of ethane content in CBM. ISO 6974-1, ISO 6974-2 and ISO 6974-3 are also applicable to the determination of ethane content in CBM.
c) Propane
ISO 6974-4, ISO 6974-5, ISO 6974-6 and ISO 23978 are suitable for the determination of propane in the range of 0,001 % to 3 %, 0,05 % to 10 %, 0,001 % to 5 % and 0,02 % to 10 %, respectively. Generally, the propane content in CBM is basically lower than 1 %, and in a few exceptions, not higher than 10 %. Therefore, ISO 6974-4, ISO 6974-5, ISO 6974-6 and ISO 23978 are able to meet and applicable to the determination of propane content in CBM. ISO 6974-1, ISO 6974-2 and ISO 6974-3 are also applicable to the determination of propane content in CBM. d) Butanes ISO 6974-4, ISO 6974-5 and ISO 6974-6 are suitable for the determination of butanes in the range of 0,001 % to 1 %, 0,01 % to 2 % and 0,000 1 % to 1 % respectively. Generally, the butanes content in CBM is basically lower than 1 %, usually not higher than 2 %. Therefore, ISO 6974-4, ISO 6974-5, and ISO 6974-6 are able to meet and applicable to the determination of butanes content in CBM. ISO 6974-1, ISO 6974-2, and ISO 6974-3 are also applicable to the determination of butanes content in CBM.ISO TR 7262 pdf download.ISO TR 7262 pdf download
