Pros
Starting your career with SLB is fantastic as it gives you exposure to the industry like no other employer can, this can set you up for a fantastic a rewarding career in the industry either within SLB or externally. It's a dynamic work place and it's great for people who like change and constantly learning new things. Salary packages are always above the industry average and your career path can be very flexible and diverse (eg. moving into lower management, then to personnel or supply chain, then technical etc).
Cons
Work / life balance gets very challenging as you move away from the young and single bracket. Long hours can make the salary less competitive. Career progression after the graduate program can be difficult to manage to continue moving up the ladder while other less experienced people will be promoted well above your grade level (maybe it's more to do with being in the right place at the right time after the fixed step program although it's still very frustrating). Needing to adhere to all the 'systems' from HSE, quality, finance, reporting etc it gets very tedious.