Oh, absolute -- petroleum has skyrocketed in the past decade (though what happens as petro cos start running into capex conflicts is open, and the current price crash is likely not playing well).

But there was a long dry spell from the late 1980s through the 1990s where those jobs, especially in the US, were very, very hard to come by.

That said, I'd love to check my statements against historical salary data for the field.