Pros
Schlumberger is a highly international company that offers motivated employees with exceptional opportunities for job growth and travel and will give them responsibilities at a young age. They combine strong technical offerings with shrewd market positioning, and at the top level are extremely well managed. I find the company to have a lot of professional integrity and pride.
Kontras
High turnover of mid-level management in my segment has made long-term strategy and standards somewhat incoherent, undercutting the efforts of the competent technical staff. Work-life balance is generally poor. Frequent relocations make it difficult to build a life outside of work. Finally, as with any big company internal processes, bureaucracy and politics drain a lot of one's time and energy.