This book addresses 200 case studies concerning production optimization and field development with emphasis on carbon management, energy efficiency, economics and risk analysis. The case studies, though often simplified, deal with real field problems or studies typically encountered in the upstream and will prove useful to the reader facing similar situations. In solving the problems, analytical equations and a hands-on approach are often used, this should facilitate the understanding of the fundamentals. Of course, many problems are solved with the Excel spreadsheet and commercial simulators. I do believe that this book is perfect for the young engineers of the upstream sector and for the students in petroleum engineering.