Pros
Having worked for a multitude of Fortune 500 companies, working for SLB was a revelation. The training is superb, graduates undergo a fixed step training program and learn about all aspects of the Oilfield, whereas even mid-career hires get fantastic training. I personally had 11 weeks external training last year, the company average appears to be 4 weeks training, of your own choosing. Recognition of hard work does not seem to be a problem, just ensure that you don't expect people to give you something for nothing, if you do something good, ensure everyone knows! The company very much employs 'Type-A' personalities, so you need to be driven and motivated to work here. The career advancement opportunities are huge, with no real boundaries to where you can go. Not only this but Schlumberger is seen as one of the best places for producing quality employees, so having SLB on your resume certainly makes you attractive to other Oil & Gas companies.
Cons
There appears to be a significant difference within job satisfaction when comparing field engineers and office workers. The office guys have a much better time, more recognition and more career prospects with good health and safety measures. This does not appear to be completely similar with field workers. Remuneration is not as good as competitors, but get yourself on an IM contract and it all gets good again. Internal services such as IT are way behind the norm as all of the good people get sent to clients, the average people are left behind to run the business inside.