Multi stage interview process. Found Schlumberger at a career fair, had a great conversation, and went to their info session the next day (I think this is very important). Two weeks later, I was called in for an on-campus interview, which pretty much consisted of going through my resume. Two weeks after that, I was flown out to Houston for an interview there. The first day was just a site tour and an info session (pretty much the same one as before). The next day was a 7 minute presentation, followed by four 30-45 minute interviews. These were both technical and behavioral. Within two weeks, was offered a full time position.