Shell has a contract with Bristow for their Citation executive jet. Interesting when Caverton also has a fixed wing division. I wouldn't think Bristow would be interested in working for Shell in Nigeria after their previous experience and having just lost the SNS contract to DanCopter.
The joker in the pack at present are CHC who will likely get their AOC again soon with new Nigerian partner Jagal after their mutually disastrous partnership with Aero Contractors.