You can post for many different roles and are not limited to the type of role for which you originally got hired. She'll has a good education reimbursement program. Also will give you credit for purposes of vacation for previous applicable work experience so you may end up with 4 or 5 weeks of vacation.
Cons
Can be very demanding. Don't expect a 40 hour workweek if you want to get ahead. Can be tough to implement new and innovative ideas even though Shell encourages it.