Ventajas
Company has excellent training programs and reasonable benefit packages (although sometimes HR does not share all the information voluntarily and it is left to employees to find out and ask for them!)
Desventajas
Company has become too big and very hierarchical. Too many layers of management. It is easy to get into a management role ( since there are just too many management roles to fill!) but it doesn't mean much since you are not really developing any valuable skills which would help you in the outside market. The skills which are developed are Schlumberger specific or oilfield service company specific at best. If you are involved on the operation side there is no work-life balance and no respect for people's personal time. You carry your laptop everywhere and are expected to be available no matter if it is evening, weekend or on vacation.