Depends on what you mean by "basic work" - most of oil and gas leadership comes ...

Depends on what you mean by "basic work" - most of oil and gas leadership comes from the engineering and geoscience side of the house.

Jeff Miller of Halliburton was a field manager.

Mike Wirth at Chevron is a chemical engineer and Chevron lifer.

Ben can Beurden of Shell is a chemical engineer and a Shell lifer.

Clay Williams at NOV is a petroleum in engineer.

Bob Dudley at BP is a chemical engineer and a BP lifer.

Paal Kibsgaard at Schlumberger is a petroleum engineer.

Ryan Lance at ConocoPhillips is a petroleum engineer.

I could go on, you get the idea. These CEOs have definitely been in the trenches.