Considerations for Coalbed Methane in Kansas, Based on the Kansas Coal Resource

L. L. Brady
Kansas Geological Survey, Lawrence, KS

Coal resources in Kansas generally are present in an area east of the Nemaha Uplift and are mainly Middle and Upper Pennsylvanian in age. Within this area, an estimated 16+ billion tons (15 billion metric tons) of coal resources [deeper than 100 ft (30 m)] exist in the Forest City Basin. This coal resource is present in 27 coal beds. A coal resource of 37 billion tons (34 billion metric tons) of deep coal is present in the Cherokee Basin in southeastern Kansas and is represented by 26 coal beds.

Apparent rank of the coals are generally high-volatile A bituminous in the southeastern part of the state, and ranges to high-volatile B bituminous in the northeastern part of Kansas. Values of vitrinite reflectance (Ro max) in Kansas coals, often suggests lower rank than rank determined by moist, mineral-matter-free Btu values.

Pennsylvanian coal beds in Kansas are widespread throughout the coal-bearing area, but most are thin [<2 ft (0.6m)] with limited areas ranging up to 5 ft (1.5 m) in thickness. Based on an earlier resource determination, an estimated two billion tons (1.7 billion metric tons) of coal is present in the Kansas resource with a thickness of 42 inches (107 cm) or greater.

Key to correlation of the various coal beds are the highly radioactive “black shales” that usually occur in the Kansas cyclothem a short distance above most coal beds. Certain key radioactive shales are widespread throughout the area and provide the marker beds on gamma-ray logs for correlation.

AAPG Search and Discovery Article #90903©2001 AAPG Mid-Continent Meeting, Amarillo, Texas