"Rumor has it that the 407s will be phased out since all oil ops have to be in twins.
Anyone want to confirm ? "
That was the rumor when I started with PAAN in '07, and even then people were laughing at it, since they had heard it when they started years before I did. So the rumor is at least 10 years old. Off and on during my almost 5 years with PAAN the rumor would resurface, every time it was stronger and more plausible. Nothing ever happened.
What it boils down to is the contracts. PAAN/Bristow is not willing to spend the money on bringing in light twins on a contract that is rolled over yearly. They want 5 years or so to be sure to get their money back on the investment. Chevron being chevron, they can't plan further ahead than next monday, so there the matter rests.
And don't forget about the 206L4s. But the machines are in dwindling numbers, as the years of hard work are catching up with them in the form of cracks etc. Soon there will be no aircraft left to fly...