Djebbar Tiab is Professor Emeritus at the University of Oklahoma, where he served as Professor of petroleum engineering from 1977 - 2014. His B.Sc., M.Sc. and Ph.D. are in petroleum engineering. He is GM and Owner of UPTEC (United Petroleum Technology LLC), a training and consulting company. He has taught graduate petroleum engineering courses at the African University of Science and Technology since 2008. Before joining the University of Oklahoma, he was a Research Associate and Assistant Professor at the New Mexico Institute of Mining and Technology. Djebbar worked in Algerian oil fields for Alcore S.A. as well as for Core Laboratories and Western Atlas as Senior Reservoir Engineer Advisor. Dr. Tiab has taught courses on reservoir engineering, production, well test analysis and reservoir characterization, and authored/co-authored over 260 technical papers on pressure transient analysis, dynamic flow analysis, petrophysics, natural gas engineering, reservoir characterization, reservoir engineering, and injection processes.Erle C. Donaldson began his career as a pilot plant project manager for Signal Oil and Gas Research in Houston, Texas. Later he joined the U.S. Bureau of Mines Petroleum Research Center in Bartlesville, Oklahoma, as a project manager of subsurface disposal and industrial wastes and reservoir characterization; when the laboratory was transferred to the U.S. Department of Energy, Dr. Donaldson continued as chief of petroleum reservoir characterization. When the laboratory shifted to private industry for operations, he joined the faculty of the School of Petroleum and Geological Engineering at the University of Oklahoma as associate professor. Since retiring from the university in 1990, he has consulted for various oil companies, universities, and U.S. agencies including: the Environmental Protection Agency, the U.S. Navy Ordinance Center, King Fahd Research Institute of Saudi Arabia, and companies in the U.S., Brazil, Venezuela, Bolivia, and Thailand.