Pros
If you're into the oil industry and enjoy hands on work, it doesn't get much better than Schlumberger field. That said, you will be working in some of the harshest, dirtiest, most extreme environments on the planet. In these places, you, as the lead engineer, will be dealing with clients ranging from clueless to nitpicking, with bosses overbearing to useless, and managing crew that can be 30 years more experienced or brand new green hats. Do your time here and you will learn all about people management on ever side, but only a dash of engineering and science. And it will be highly specialized science, so don't expect to take much of it out of the oil industry or even oil services industry. But it WILL be doing time. Don't count on getting your days off - only count on getting paid.
Cons
Depending on who's reading the statement I wrote for Pros doubles as a Con list. Just reread that and figure it out.