I did 2 trips offshore as an engineer on a platform off of Louisiana. Was incredibly boring and easy work, they paid double time and all your food, etc. was free. The crazy part was all the simulations you had to get certifications for, including the helicopter crash/submerged certificate. They had a real simulator that simulated a helicopter sinking and flipping upside down in a giant pool. You had to escape in under a minute. It was so easy to get disoriented. I saw a few people fail and give up completely because it scared them. The only way to get to the platforms was by chopper.
The rig i was on was a platform with a foundation, it barely moved and was in relatively shallow water. We used to fish around its base and catch king mackerel and grouper; i think most don't let you have any "fun" on the platforms anymore. We would jump off the lower levels and swim, but you had to watch for sharks.
No drinking and you pretty much worked 16 hour days, it's not like you had anything else to do. No cell phones either, mainly due to the cameras. But we had Xbox and PlayStation.
I still remember i worked with this petro engineer Derek, he was a ironman competitor that was world class, he traveled all over the world. He would literally run in a 50 yard circle along the platform for hours at a time to stay in shape.
We ate really well, filet mignon and lobster every day. Most of the guys who stayed out there for long time periods were single. You couldn't spend any money because there was limited access to internet/phones for security reasons. This guy i knew always left a list for his wife to buy toys for his return. Each trip he would come home to a new ATV/jetski, etc.