Rig Roustabout/Roughneck

by Nic m
(Sydney, NSW, Australia)

Hello i would like to enquire on the best way to go about gaining a job offshore as a
Roustabout or Roughneck. I have no drilling or offshore experience but have worked on many construction sites in Australia and y previous career was in the Army where i worked in Combat Engineers and Special Forces.I have operational experience in the Middle East and Pacific. Currently i am a Personal Trainer.
Is it always necessary to start as a roustabout or is that depending on the company.
What courses and research should i undertake to enhance my chances??