global,
There's no doubt that Nigeria's not the safest place to work, Aero only has 1 AW139 actually on contract (for Total) and as far as I'm aware they have no other major oil contracts for now. However, I don't think Aero will go down the tubes and even if they did there are 3 other operators here you could probably move to.
Aero has a good infrastructure because they have hangars and workshop facilities in Lagos, Warri (where they own the old airstrip and have hangars, something no other operator has) and Port Harcourt. I've also heard they have paid salaries late occasionally lately, but with that great infrastructure they have they should eventually pull through and even with all their financial problems, must be very tempting as a partner to the likes of PHI, NHV and Era if they want to expand into this part of the world.
I've worked in the Middle East, Africa, Europe and America and still much prefer here to the Middle East. Nigerians admittedly can be a bit volatile, but they're also funny, friendly and welcoming. You won't see much of the country because of the security problems, but it's always warm and the money's ok, so I'd give it a go. If it doesn't work out for you there are plenty of other opportunities both in Nigeria and other countries for 139 engineers