Petroleum Geoscience is the study of geology and geophysics in determining the origin, distribution and properties of petroleum and petroleum bearing rocks. It is an invaluable reference for petroleum, chemical, process engineers; chemists; chemical technologists, analysts and students in these disciplines. Petroleum Geology is principally concerned with the evaluation of seven key elements in sedimentary basins namely, Source, Reservoir, Seal, Trap, Timing, Maturation and Migration. An attempt is made in this book to introduce to the readers the important aspects of Petroleum Industry. The aim of this work is to provide the communication between those contributing to the Petrochemicals directly of indirectly, i.e. engineers, students, oil companies, equipment manufacturers and last but not the least, producing and consuming countries.