I had two interviews with Swift but in two separate years.
The first interview I received through getting to know the lead recruiter at a career fair dinner. I interviewed with one of the chief reservoir engineers and one of the younger engineers. I was mostly asked questions by the chief reservoir engineer. Questions were mostly conversational and the atmosphere and attitude made it very easy to talk. The questions were a little generic (i.e. Tell about a hard time in a group, what discipline are you interested in...). I followed up with a thank you email and the lead recruiter replied to me but I did not hear anything significant for a couple of months until I received a letter in the mail about being denied the offer.
The second interview I received by seeing the same chief reservoir engineer again at the next year's career fair. He helped to get me through the new lead recruiter and onto the interview schedule. I was interviewed by the same chief reservoir engineer and a different young engineer. This time the young engineer asked me questions because I knew the senior engineer. Again, the interview was more conversational but the atmosphere was a little less day to talk under as the first interview but it still went well. This time I did not hear back from the company at all and I was extremely disappointed in the way it was handled.
Even though I had a negative end to my experiences, I think I would interview again, given the opportunity because I know the company culture sounds wonderful and right up my alley.