Hydrocarbon is basically defined as a compound of hydrogen and carbon. They are the basis of nearly all our energy resources. Knowledge on their origin, features and phase behaviour is fascinating from the point of view of physical chemistry. At the same time this knowledge is of much value to the oil and gas industry. This book showcases several topics ranging from origin of hydrocarbons to the process for hydrocarbon exploration. Presence of polycyclic aromatic hydrocarbons in soil and their impact on environment have also been presented. This book will serve as a supportive reference tool for researchers and students, as well as experts, associated with both academics and industry.