Thank you for your thoughtful comments. A couple of points--
I am aware that the seismic survey in the Atlantic OCS is quite out of date in terms of how much oil is located where. However, the update on economically recoverable resources for the Atlantic is from 2014, and based on current extraction technology. Best knowledge to date is that the bulk of the oil is deep and ultradeep water, which is expensive to extract. New techniquies may find shallower plays, it is true. But that is not something we can comment or speculate on until the survey is done. I wrote the post with best avalible knowledge, but you are correct to point out that it is old.
Regarding Saudi Arabia, the dynamics of giving up market share are entirely different in a world were oil consumption will be finite based on environmental constraints rather than a world where oil will be consumed to the last drop. Thirty years ago, yielding market share merely meant that Saudi Arabia had higher margin on the oil that it produced. Today it might mean that Saudi Arabia, not a higher cost producer, will be left holding the bag. Even if Saudi's reserves are overstated, new U.S. oil is still too high up the cost curve to be the next best option.
U.S. offshore oil--indeed, oil worldwide--is exhibiting diminishing returns in terms of both energy inputs and dollars spent to extract a barrel of oil. This dynamic cannot be changed. Investment costs are increasing and long term, stable high oil prices will not come rushing in to cover this. While the future will no doubt see prices spikes, the long term trend for oil is down. For infastucture projects with such upfront costs, long lead time, long project life the smart investor should be putting their money in projects with increasing returns instead.