If you recall in The Usual Suspects, 'Verbal' reminiscing about picking coffee beans back when he was in Guatemala...
Sev claims to have had an interesting career in the subject of the day, spanning the world, and yes, oil was one of them. I do believe it was with a rig, but I'm not sure, because he used to be until a climatologist working for the Federal Government at least since Reagan and a Democrat until Clinton fired him (hence his current disdain for the party), so more in the science portion of the industry I reckon.
Anyways, he was going on about being an oil expert and how we now find oil in layers where decaying algae had become part of ocean sediments in the way back when.
I had brought up how it is oft found in upwellings where crustal plates grind up against each other, and he had not only not heard this, he firmly denied that this was a possibility, and rather adamantly at that. That's like somebody saying plains bison can't be found on the prairie. It's not exactly a minor fact that somebody in the industry would overlook or forget. You want to go looking for it, you go to places where the tectonic tango is going on.