I Calgary, AB .. lived in Regina, SK .. I know more people that worked the rigs then I do people who work in the office.
Barriers to entry:
1) Housing. The biggest barrier to most work in the Canadian Oil Fields is finding a place to live near the work. There are very few (and very competitive) jobs in the major cities, but smaller centers have more jobs then they have houses.
2) Certifications. Most employers will list what certifications they want on their websites.
So. The question is .. how much money do you want to make? I know people who clear 6 figures, with minimal experience, and a few weekends of safety training.
The work isn't for everyone. You live in shitty little camps, working very long hours .. but you get paid for it. And you do get time off. Lots of guys have houses in Calgary, and will spend a their off time partying in the city for a few weeks before heading back to camp.
I also met a guy while travelling Australia. He spent a few years working the Saskatchewan Oil Fields, then got a job in Australia. Makes his 6 figures, has his home in Brisbane, and spends his off time travelling the Gold Coast partying with backpackers.
If you're dedicated - you can transition into sales. I am taking the Dale Carnegie Course with a bunch of oil services salesmen .. and they live a pretty rock-and-roll lifestyle. Living in the city, lots of hookers and blow, with 6+ figure incomes, and still only a few weekends of safety training.
So ya .. find out where you think you might want to work .. and see if you can find a place to live there. Don't fret to much about "finding a job" and "having the right certifications".