For the Elk area, they had a very large fractured limestone with some limited porosity. The Elk area is I believe a reasonably good sized commercial discovery but does require more wells and long term flow tests to confirm.
The article was supposed to be about the Antelope area but was actually talking about the Elk play. Even If the article were supposed to be about the Elk play, it would be somewhat unfair as it implies that is certainty that the Elk play is not economic and won't be able to sustain good natural gas flows. Given the Elk results to date, this does not seem to be the case at all.
The Antelope area is a reefal limestone formation with hundreds of net feet of high quality dolomite with 12% porosity - including a large amount of vuggy porosity. Permeability in the high quality dolomite area is very very high such that during the flow tests, when they shut the valves, pressure instantaneously recovers. With 700 mmcfg/d flows, this only happens in reservoirs with very high permeability. As such, the Antelope play is a world class play with multi-TCF potential that can be recovered with a small number of wells.