Petroleum is a yellowish-black liquid which occurs naturally in the geological formations beneath the Earth's surface. It is formed when large quantities of dead organisms such as alga and zooplankton are buried under sedimentary rocks and subjected to intense pressure and heat. Petroleum is a mixture of different hydrocarbons having different molecular weights and physical properties. Petroleum science and technology refers to the various processes related to the exploration, production, transportation and refining of petroleum and its products. These activities are divided into different sectors, namely, upstream, midstream and downstream. It is an interdisciplinary field which encompasses the principles of geology, drilling technology, geostatistics, railway engineering, logistics and transport, economics, production engineering and chemistry. The various sub-fields of petroleum science and technology along with technological progress that have future implications are glanced at in this book. It includes some of the vital pieces of work being conducted across the world, on various topics related to petroleum science and technology. This book is a resource guide for experts as well as students.