Worth bearing in mind that a lot of the Oil Co insist on 'new tech' ac (139, 225, 175 etc) when actually if they wanted to reduce cost, something like an L2 or a C+ would probably suffice for a lot of their needs and give them that 20% cost reduction they want.
The logistics aspect is the same, moving XXX people from A-B, it's just that the cost is different and the ac are older. It can be argued there is a safety change between say and L2 and an EC225 but the incident rates for both types overall are still very low.
Moving to new tech in many cases is a vanity/
PR project with associated vanity project costs. An L2 these days is about $8m on the open market (purchase) while a used EC225 is closer to $20m. No prizes for guessing which one is more expensive to rent and where that cost ultimately ends up.
Helicopter operators are not in a position to simply reduce costs like that (good luck trying to refinance helicopters on lease or change unionized pilot/ engr salaries). I suspect that what will happen is less exploration rather than the same amount with reduced rates/ costs.
Edited to add that I work for an operator and I'm happier when they pay more for new ac.....
Edited second time to agree massively with Albatross' comment!