Avantages
Schlumberger is never short of technical challenges, and for software engineers, that is a dream life... Solving one problem after another. Often, these challenges span multiple product lines, and you will be rewarded with recognition and even bigger challenges if you are able to master the politics associated with these problems. It can be quite fun, but does require extraordinary energy with the silo'ed product lines.
Inconvénients
The HR policies for software engineering are out of date, with a stick and carrot approach to appraisals. This has caused a culture of pleasing your manager (or their manager) and helping them with their annual objectives over solving the problems that clients or the business needs. Yes, this can work out when the annual objectives match client needs, but in software, the problems change so rapidly the team needs freedom and autonomy to respond without fear of their boss's reprisal.