Potential Coalbed Gas Resource in the Hudson Hope Area

Barry Ryan¹ and Randy Karst^2
1 Ministry Energy and Mines BC, Victoria, BC
² Canadian Spirit Resources Inc, Calgary, AB

The Gething Formation, which underlies an area around Hudson Hope is perspective for coal bed gas (CBM). The formation contains a number of thin seams with cumulative thicknesses that average about 8 metres; but range up to 17 metres. The area is east of the disturbed belt and has experienced little deformation. Coal rank varies is higher than high-volatile A bituminous. North and south of Hudson Hope the formation dips moderately to the east and not much of it is in a prospective depth window for CBM. However over the Peace River Arc, in the Hudson Hope area, the formation is shallower.

The CBM resource in the area is calculated using rank, depth and cumulative coal thickness data, obtained in part from Geophysical logs from 121 holes. Gas contents were estimated using an equation that predicts approximate saturated gas capacity of coal based on rank and depth. Data from a 1981 coal exploration report indicate that the coals may be saturated below 200 metres.

A previous study estimated the resource in the Gething Formation at 34.9 tcf to a depth of 1800 metres. This study estimates a potential resource of up to 25 tcf. and concentrations in many areas of more than 10 bcf/section.

Cleats in seams and fractures in the surrounding rocks were measured as a start to predicting seam permeability. Seams contain well-developed face and butt cleats with an absence of conjugate shear fractures. Face cleats are normal to the structural trend of the disturbed belt.

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