First off, Congrats and Welcome!
I don't know too much on investing in canada, and their tax laws/implications. However I'd look towards the canadian branch of Vanguard. Low fees = :)
Also, one thing you may not have though of yet, is to advertise your ability to speak Chinese (Mandarin, or whatever). I'm assuming you know it, since you've worked there for 3 years. (If not, work on it like crazy while you're still there.) Even if you only have a basic understanding, businesses may keep you on in an on-call basis, and pay you to translate. I'd look to businesses that deal with everyone, and/or are bigger ticket items. So car dealerships, city hall, real estate offices, etc. Of course this will only work if there are a lot of Chinese immigrants in your area. But could be a great side job.
My other thought is, if you can live on so little, teaching still pays pretty well, and your FI won't really be delayed too much. I'd rather work 15 years on a job I like, than 10-15 on a job I hate. So while an oil rig may speed up FI, if you enjoy your job (i.e. teaching), I'd go with that. Remember, if you can find a job you like, you'll never have to work a day in your life.
Hopefully others can give you a better answer to your actual question, but just thought I'd give my 2 cents for your situation. Good Luck!