I think you will be able to do the job for 5-6 years and then move on.
It also depends where you are flying offshore.
I used to do on average 5 landings per flight hour, I am told Aberdeen does one landing every flight hour on average.
Offshore do use the helicopter like a bus or fixed wing with the only difference of you landing on postage stamps.
It will help you to learn about twin engine aircraft and working as a team as well as the IR ticket.