Oil and Gas Community

I am interested in starting an oilfield career as an equipment operator trainee/laborer in the US.
Basically learning all aspects of fracturing, cementing & driving trucks.
I hold a valid CDL A license with XT endorsements, clean MVR and criminal, construction exp., can pass background check & ability to relocate.
I have some college, but no degree & no previous oil related experience.

Is there a degree in a specific field that companies are looking for pertaining to this job?
Say an associate's degree of applied science - process technology/energy operations to start?
Or will companies train you completely without having a degree?
Are there other certifications that are needed before applying?
Is age a factor? I am 34, but in the best shape of my life.

Any answers, advise or opinions would be greatly appreciated.
Thanks,
Dustin