An intermittent but longstanding theme here on theoildrum is that dollars do not sufficiently inform us of the long term details of energy depletion, and that the inexorable race between technology and depletion can be better understood using biophysical methods. Essentially this post suggests that it is requiring more and more energy to procure the same amount of natural gas in Canada, and this trend will likely continue into the future. This update makes the initial analysis too pessimistic on the rate of EROI NG decline but also too conservative on the absolute level of energy return. It is going to be a very interesting few years as Canada declines, Barnett peaks, and Haynesville and other unconventional plays ramp up. The treadmill spins on.