More energy than is required to refine it from crude, perhaps, but far less than went into creating that crude. If I get a tank of compressed air, I'll get more energy out of it than it takes for me to turn on the valve.

Are you referring to the production of oil, as in developing reservoirs, and refining it? Yes, then obviously.

Why buy something the same size as your thumb, when you have a thumb???

ummm, what?

Well double dumb ass on them! (Ooo...Roller!)