Pros
Schlumberger is a lifestyle. If that lifestyle suits you, you'll be rewarded very well. Schlumberger allows you to live in many different locations around the world and experience many different cultures which ultimately help you grow significantly as an individual. The technology that Schlumberger posses is very intriguing, and certainly cutting edge for their industry. You have plenty of opportunities to move up in management, and to do so quickly.
Cons
If this Schlumberger lifestyle does not suit you, there is no amount of money that will make it worth while. You do work a lot (some going 4 months without a day off, even weekend), however its a knowledge cramming period. Your sleep patterns will be abused severely at times, and you will fall out of contact with many old friends simply due to your new lifestyle.