I interviewed on campus and the interviewers were very friendly. They weren't HR and were field engineers doing the interviews. After the interview on campus I heard within a week that I had a second round interview in Brighton, CO. That interview was terribly unorganized. Several of us flew in at the same time, there was no transportation organized for us, just a suggested shuttle service to use. When we arrived at the hotel the interviewers were late and sloppy. They were eating sandwiches while giving a presentation we had already seen on campus during information sessions. After the presentation they asked us where we wanted to eat and didn't have it planned. Of course none of us knew where to go because we'd never been there.
The next morning we woke up early and went to a frac job, this was the most valuable experience of the interview. After that we went back to Halliburton's local camp for an interview, they lasted longer than expected and several people missed their flights home.