Platform crews. There are many diverse jobs on an oil platform including, administrators, engineers, scientists, drilling crews, divers and medical staff. Oil platforms can be isolated but the work is well paid.
Refinery staff. A refinery relies on a wide range of skills, including chemical engineers, environmental scientists and maintenance staff. There are also support staff like nurses and firefighters.
Other staff. As well as platforms and refineries, oil companies need laborataries, surveys and offices. And all of these are staffed with a wide variety of jobs.