Long, in-depth, difficult interviews with multiple people on same day. I was at their office for about 6 hours and interviewed with 3 managers. All questions revolve around the company S.P.I.R.I.T values. You have to provide answers that correspond how you reacted to various situations/performed in former jobs/completed tasks utilizing Safety, People, Integrity, Responsibilty, Innovation, Teamwork.
I had multiple interviews with other O and G companies in a 6 month period and this was by far the most difficult.