Brent was one great oilfield.
Its outstanding reservoir character and enviously high grade of crude contributed to its superior productivity.
And of course, that is its downfall after a producing life of less than most giant oilfields.
Prolific fields like that produce at such high rates they are enormously profitable but have the downside of having relatively short lives.
The current production in this US concentrates on low quality, discontinuous reservoirs. These have lessened profitability but are blessed with considerably longer producing lives.
We as a country will enjoy that effect for a long, long time.