static and another one is rotary. Static machinery and rotary machinery. Which mean you gonna deal with the things that is not rotating. Rotating like turbine, pump etc. That is what i see around.

mechanical,chemical,petroleum, even geology also recommended.
Yes slightly depends on the nature of the job, since o&g has a lot of scope s(downstream and upstream), the most challenging would be the upstream since that is where you get the oil pump up.
World Recession= Less demand for crude.
Unless OPEC is crazy enough to cut quota in order to balance their fiscal, and bring down the world's economy with it, which i think they will.
Hmmm, they will only offer you the job if you're an Aussie PR or citizen. If you're then i guess it could be true.
YES you do, if you specialize in geo-physics, my physic's professor is earning $$$ doing consultancy for oil companies.