Book excerpt: This book covers the fundamental concepts of petroleum engineering. It deals with basic component of petroleum upstream. The main goal of the book is to provide the student with overview of element of petroleum industry. This book is designed to familiarize the students with the fundamental aspects of petroleum engineering: Origin of petroleum and types, Petroleum exploration methods, Reservoir rock physical properties, Reservoir fluid properties, Method of oil extraction, as well as overview of petroleum geology in Yemen. The book is intended to undergraduate and graduate student of petroleum engineering department of university. It also intended to student of technical institute. The book may be also useful for petroleum engineers who work in oil industry. The book can serve as reference book for other people who are interested in petroleum industry. The book consists of 6 chapters. First chapter reviews the theoretical basic of petroleum formation. Chapter 2 reviews the basic methods and principle of petroleum exploration. The third chapter focuses on definitions and measurements of different physical rock properties and their applications in reservoir engineering calculations. Chapter 4 presents definition and determination the properties of reservoir fluids. Chapter 5 is intended to introduce the basic principle of petroleum extraction and recovery mechanisms. Chapter 6 reviews the petroleum geology and status of petroleum industry in Yemen.