Coalbed methane characteristics of Gates Formation coals, northeastern British Columbia: Effect of maceral composition

Journal Article · Wed Dec 01 04:00:00 EST 1993 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5592723

Lamberson, M N; Bustin, R M ^[1]

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1. Univ. of British Columbia, Vancouver (Canada)

Coals are derived from the thermal and biogeochemical alteration of terrestrial plant accumulations. The majority of research reported on methane adsorption characteristics of coal seams has focused on vitrinite-rich coals. However, western Canadian coals are more inertinite-rich than those of the western United States and are shown to differ in gas adsorption characteristics. The influence of maceral composition upon gas adsorption characteristics of medium-volatile coal samples from the middle Cretaceous Gates Formation of northeastern British Columbia was investigated. Lithotype (coal facies) samples were analyzed for surface area, maceral and mineral composition, and methane adsorption; standard coal analyses were also performed (proximate, low-temperature ash, and equilibrium moisture). The vitrinite content of the samples analyzed ranges from 18 to 95% (vol. %, mineral matter free); the ash yield varies from 4.4 to 33.7% (wt %). Both maceral composition and mineral matter content have an important influence on adsorption characteristics as indicated by carbon dioxide surface areas and methane adsorption isotherms. Carbon dioxide surface areas of the lithotypes range from 87 to 176 m[sup 2]/g on a raw-coal basis, and from 99 to 184 m[sup 2]/g on a mineral matter-free basis. Surface area generally decreases with increased mineral matter content and increases with increased vitrinite content. The methane adsorption isotherms and surface area data indicate that the maceral compositional variations in coal are at least as significant as coal rank in determining the potential volume of adsorbed methane and thus the coalbed methane potential of a deposit.

• OSTI ID: 5592723
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Vol. 77:12; ISSN 0149-1423; ISSN AABUD2
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600 -- Coal
Lignite
& Peat-- Properties & Composition
03 NATURAL GAS
030300* -- Natural Gas-- Drilling
Production
& Processing
ABSORPTION
ADSORPTION
ALKANES
BRITISH COLUMBIA
CANADA
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL COMPOSITION
COAL
COAL DEPOSITS
COAL SEAMS
DEGASSING
DEVELOPED COUNTRIES
ENERGY SOURCES
FOSSIL FUELS
FUELS
GEOLOGIC DEPOSITS
HYDROCARBONS
MATERIALS
METHANE
MINERAL RESOURCES
NORTH AMERICA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PRODUCTION
RESOURCES
SORPTION