--> Abstract: Evidence of Coal Composition and Coalbed Methane (CBM) Source and Reservoir Potential in Coal Cores, by Judith Potter and David Marchioni; #90039 (2005)
[First Hit]

Datapages, Inc.Print this page

Evidence of Previous HitCoalNext Hit Composition and Coalbed Methane (CBM) Source and Reservoir Potential in Previous HitCoalNext Hit Cores

Judith Potter1 and David Marchioni2
1 JP Petrographics, Calgary, AB
2 Petro-Logic Services, Calgary, AB

Previous HitCoalNext Hit is both the source rock & reservoir for coalbed methane (CBM). Source rock potential is typically assessed by desorption testing of Previous HitcoalNext Hit core or cuttings. Reservoir potential is ultimately assessed by production testing.

The cores cut for gas content testing can also provide valuable information on reservoir potential and/or differences in reservoir potential/performance between wells.

Previous HitCoalNext Hit is a bedded organic sediment and contains laminae that vary markedly in macroscopic brightness. Previous HitCoalNext Hit lithotypes are the small sub-sections of the seam within which the proportions of these bands are relatively uniform, but significantly different from the proportions in bounding beds. Lithotypes reflect the composition of Previous HitcoalNext Hit – the proportions of macerals (organic micro-components) and minerals in different portions of a seam. The lithotype profile of a seam reflects the variation in depositional conditions in the precursor mire.

Lithotypes influence gas content as different Previous HitcoalNext Hit macerals have different potential to generate and store gas. In addition, lithotypes influence cleat development, with cleat density decreasing as the brightness of Previous HitcoalNext Hit decreases.

The fractures in Previous HitcoalNext Hit (aka cleat) are the principal permeability pathways. Description of cleat spacing, length and mineral infilling offers insight to the permeability potential of the Previous HitcoalNext Hit. Cleat development is influenced by Previous HitcoalNext Hit rank (aka maturity) and by Previous HitcoalNext Hit composition, which is reflected in visible lithotypes. However, lateral permeability at lithoptype boundaries tends to be underestimated. Examples of micropermeameter tests on slabbed and polished Previous HitcoalNext Hit cores suggest that permeability at lithotypes boundaries is significant Cores will be presented from coals of different rank and from the major Previous HitcoalTop zones that are targets of CBM exploration, to illustrate features of lithotype and cleat variation. Detailed lithotype/cleat profiles will be displayed alongside the cores.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005