Petroleum Engineering Summer School (PESS) has been operating within the academic program for advanced studies of the Inter-University Centre Dubrovnik (IUC) for more than twenty five years. The interactive seminars are organized by the Executive Directors of the PESS, professors from the Petroleum Engineering Department of the Faculty of Mining, Geology & Petroleum Engineering (www.rgn.hr), University of Zagreb, and co-directors, distinguished professors from Croatian universities and abroad and professionals.