The initial interview was conducted at my university. It was a typical HR interview. I was called for a second interview which took place at one of their field offices. We were treated to breakfast, lunch, and dinner over a 2 day period where we were shown all aspects of the job for either a frack or cementing position. The process was laid back. They frequently prompted us to ask questions about everything they showed us. You seem to be evaluated constantly during the trip with a 3 member panel interview at the end where they just ask basic questions about your resume.