Global Operations
Bell206/407/212/412/AS332L, S76 & EC155
Looking at the types listed I would hazard a wild guess it might be these chaps:
http://www.bristowgroup.com/
PS. You could 'convert' the types listed above as: Escravos/Escravos/Eket/Escravos/Lagos, Lagos & Warri/Port Harcourt
It's Global with a hint of West Africa
Mind you, I could be miles out, and it could be Hong Kong helicopters, or Helicsa for all I know!