Phone interview initially consisted of competency based questions, leadership etc. Assesment day was split in to four areas- team building, tour, presentation/ panel interview and psychometric testing. Team building is the typical kind of excercise where they make you do something ridiculous and assess you based upon it. tour is a tour of the building. presentation and panel interview is easy, where you present a given topic and answer questions based on it, and again more competency based questions, some basic technical also. Psychometric testing is easy also. These people are completely out of touch with reality, so act fake and you should do well. Your peers will certainly be doing so- there were some real tossers.

I applied from my university career center. Petrofac has an agreement with the university to select two engineers from every department. A resume along with transcripts were asked for. There was no face to face nor skype or phone interview. They rely on your course work and your resume. They only have you fill in a questionnaire.