Book excerpt: This book describes procedures for determining the total hydrocarbon (petroleum) resource or resource potential in a region. Statistical concepts and methods employed in petroleum resource assessment are the subject of the manuscript, extensively illustrated by numerous real case studies. Prof. Lee's computer-aided Petroleum Information Management and Resource Evaluation System (PETRIMES) methodology has been adopted by governments around the world and by major multinational oil companies to perform resource assessment and to predict future oil and gas production. Though this methodology is so widely used, there is no "user's guide" to it, and this book will be the definitive resource for PETRIMES users.