re: Chevron Eyes US Gulf Growth, Plans New Wildcat

Davy Jones is a much different reservoir than Shenandoah.
They are reasonably comparable in total depth below sea level, but DJ was in only 10' of water and Shen is in ~6000' of water, meaning you're dealing with 6000' less of rock overburden at Shen.
DJ also had little to no salt above the formation, where as Shen has ~20,000' of salt above it. Salt is lighter than rock, which reduces the overburden pressure, and acts as a thermal wick, reducing the downhole temperature.

The large salt body is one of the biggest contributors to why Shen has such a unique oil quality for this depth, as another poster had mentioned.

And although Shen requires a 20k psi tree like DJ, it is just barely above the 15k surface rating and will actually produce the majority of its life under 15k. The 20k tech is just needed for the completion and production tree.