I've heard that pipeline can be very good money...but it's absilutely a case of feast or famine. Go hard for six months, and then sit for nine.
Rubio3jef is accurate in the differences between drilling and service rigs...although there are some "carrot puller" single and double drilling rigs that run their hands just as hard as a service rig. They don't run leasehands either, so you'll be slinging tongs just as fast as the motorhand can train you (mostly 'cuz he doesn't want to do it)
To be honest with you, trying to describe working on a rig is like trying to describe an elephant to someone who's never seen one. We can talk 'till we're blue in the face, but there's no way to truly understand what it's like until you've done it.