This book highlights the fundamental and applied aspects of geoscience that an engineer and geologist would need to be effective in the upstream petroleum industry. Geoscience is integral to exploration and production of petroleum, and a good understanding of the subject enables petroleum engineers to execute their tasks effectively in an interdisciplinary and collaborative environment. Most petroleum engineers lack a geological perspective, owing to their increased focus on core engineering disciplines, and evaluate rocks from a mechanical object. At the same time, books in geoscience which are currently available for undergraduate education are written for educating geologists only. This book aims to provide geoscience fundamentals as required by engineers and geologists to prepare for a career in the upstream petroleum industry.