Well Bristow are happy to put people through a command course in about 2500 hours, and 4 years, but whether you're up to it is another thing. You have to do a load of what are called QFR's qualifying flight reports, with a training Capt etc, and they monitor your progress.
CHC have minimum hours before you're eligible for command. The OGP requirements have a lot to do with hours requirements.
Minimum of 4 years I reckon. It all depends on ability and command positions becomng available. 3000 hours. Mind you, flying Southern North Sea is different to flying out of ABz. The aircraft are smaller, you spend a lot less time in the cruise down south, more landings etc, and i'm told even the night flying is different due to the lack of light from flare stacks.
I've never flown out of Abz so only repeating what i've been told.
I would guess that 3000hrs up north is about 1/4 the number of landings of that you'd do down South in the same hours.
Most, if not nearly all of the guys I started with are now upgraded or in the process of being upgraded, and thats 4-6 years.