SAR in the GOM is sparse at best. The USCG has the responsibility, but they don't get started very quickly. The only saving graces here is that there are lots of helicopters and boats out there, and the seas are generally comparatively benign. I've gone out on searches on which the Coast Guard was called first, and we only started an hour or more afterwards, had to fuel, plan, etc, and were still the first on the scene. The Coast Guard will come, eventually, but it apparently takes awhile to get things started.
I'm not aware of Exxon using Era for anything in the GOM, nor had I heard about any 332Ls flying in the GOM, but I could be wrong. In any case, there is lots of drilling going on far out there, and there is no dedicated SAR for any of it. We're going out with one-way fuel, little or no weather reporting, no ATC coverage (neither radar nor radio) but it's all perfectly legal. The oil companies have no responsibility for any of this, of course.