CBM wells are cheap because they are usually shallow Deeper wells tend to have lower coal permeability and productivity Low permeability is the weak point (Achilles heel) for CBM ventures, and success will entail finding regions of enhanced permeability, utilizing horizontal wells with the option of fracturing these wells, and possibly in "creating" permeability by new-paradigm methods such as shear stimulation and branch fracturing This paper discusses the role of permeability in choosing CBM completions, as well as examples of those completions from around the world The guidelines offered are new and practical (including perm bands and a decision tree), and should benefit any CBM completion strategy (C) 2010 Elsevier By. All rights reserved.