As you may have read already from other comments, the two day interview process is very laid back. Meet-and-greet, presentation, and dinner on the first day and field or shop visit, lunch, and out-interview on the second day. What I came to find out from the region I went for (Northeast) is that they do almost everything the same I expected from reading glassdoor comments about field engineer interview process, but the out-interview a bit different. It was 45-60 minutes long instead of the 15 minutes I thought it would be. The interviewer made all the same behavioral questions from the first interview I had on campus, he asked technical questions related to my field of engineering and also about the presentations and shop visit, and gave me a short written exam with electrical and mechanical problems to solve with out a calculator. The technical questions were very basic (i.e. difference between pump and motor, standard household voltage/freq, what does bentonite clay do when drilling). The written exam had a problem of solving for total resistance of a simple circuit, one of hydrostatic pressure, one of step-up transformers, and one wireline problem about calculating the voltage needed to power a tool down the hole at certain distance.