This is a serious issue. In those countries where the oil company is strong enough and has a good safety policy then a video brief of all passengers is carried out in controlled and effective environment (not standing around the helicopter in the rain - which also happens).
This quality of the video brief is also important - it's a safety video not a promo film for the oil company.
Shell is one company where
every flight is properly briefed and many others have the same policy.
A good briefing combined with good quality (OPITO standard as per OGP) underwater escape training is the best survival tool you can give any offshore passenger. Check out
www.ogp.com
OGP provide extensive assistance to oil companies engaged in the use of helicopters. Engage with them and you will get a good idea of what should be done.
G