Regional Trends in Gas Quality

Conventional gases have higher BTUs in southeastern Kansas, indicating a greater proportion of heavier hydrocarbons -- a trait that is consistent with the inferred greater maturation in this region. Shallower Pennsylvanian gases from the Missourian and Virgilian part of the section have greater percentages of noncombustable gases, which significantly lowers their heating value. Heating values for coalbed gases mimics the trend established by the conventional gases. Inasmuch as helium is not easily retained by adsorption, coalbed gases generally have low helium content, but the presence of helium in some coalbed gases suggests leakage from conventional reservoirs with well completion.


Last updated May 2004