I lobbied my university heavily to be selected for the interview. I have read on here that the interview consist mostly of competency based questions. When I met with the Exxon geologist who did the interview I found out that the entire selection process is based on your ability to show what research you have done so far and your progress toward your graduate degree. This man has been the main recruiter for Exxon US for almost 8 years and 60% of the geoscientists in the company were hired by him. He was very nice and informative but unless you are very bright and accomplished you don't stand much of a chance. Approximately 10% of those interviewed are considered for a summer internship. Of those interns 60% are offered positions. Good Luck!