James W. Schmoker Thaddeus S. Dyman Vello A. Kuuskraa 1998 <p>This final article on the outlook for U.S. future natural gas supplies expands on the concept of the natural gas resource pyramid. A series of poorly understood but potentially significant emerging gas plays is introduced. These plays reside at various levels within the resource pyramid. These emerging resources include sub-volcanic gas, shale gas, deep coalbed methane, and unrecognized tight gas sands.</p> application/pdf en PennWell Corporation Diverse gas plays lurk in gas resource pyramid article