chopperman - I gave a classic example in immediately after my statement repeated (albeit with a spolling irror!).
OGP has a series of standards for oil company helicopter operations and single engined piston rotorcraft at night over the sea is very non-standard! Furthermore Apache have recently entered the offshore market in another country and negotiated contracts without clauses that the members of the local offshore oil & gas operating association have adopted as local standards for oil & gas operations.
I'm not suggesting that they would knowingly contract an operation outside of local mandatory regulations (and sorry if I may have implied that), just that they are unlikely to pay for things they aren't forced to pay for.