This is a comprehensive and current introduction to the upstream industry, drawing together the many inter-disciplinary links within the industry. It presents all the major stages in the life of an oil or gas fields, from gaining access to opportunity, through exploration, appraisal, development planning, production, and finally to decommissioning takes place. The book is written for industry professionals who wish to be better informed about the basic technical and commercial methods, concepts and techniques used in the upstream oil and gas business.