[thackney]

This may help explain the difference and why one cost is discussed separately from the other.

http://www.ey.com/Publication/vwLUAssets/US_E_and_P_benchmark_study_-_June_2012/$FILE/US_EP_benchmark_study_2012.pdf

[American Constitutionalist]

So from reading this am I correct to say that the faster fall in production of the shale oil wells is not due to all the oil being drained out compared to traditional oil wells, but ? the ability to get at the rest of the 80 % of potential oil that is left in the play with current technology.
So the future prospect of this all in spite what OPEC says and the other propagandists say, we will have plenty of oil in the future and production if we are able to get at it when the technology improves.
Hope they manage it well to where they can keep the current production going over all until they can improve on that technology.