Job Data in the Offshore Oil Industry - Help Requested

Dear All -

I am looking for some published data that would touch upon or that analyzed the “progression” of persons working offshore. For instance, if someone started as a roustabout, assuming they liked their job and they were a hard-working employee, what would be their natural progression as far as job titles? I realize the economy of late is a factor and of course the [I]Deepwater Horizon[/I] and the resultant changes in the permitting system have an immediate impact on this, but I would like to try, at least for the moment, to assume those items did not exist. I am hoping that any data that is actually located is from a time that predated these two major factors. Also, if the data does not differentiate between offshore and onshore but does cover the oil exploration and production areas, that is fine as well. I would like to keep it to US data.

Thank you to any persons that can help me answer this inquiry.