Acquisitions and divestitures are common occurrences in the international oil and gas industry, ranging in size and complexity from transformational mergers between supermajors to transactions at an individual asset level. They are used in order to manage both costs and risks. Although the recent oil price slump has somewhat reduced the level of transactional activity, that level is expected to increase again in the near term. Low oil prices are creating an increasing number of distressed sellers and an increasing number of opportunistic buyers, including some that have not traditionally participated in the upstream oil and gas industry. Moreover, any 'new norm' for oil prices - even at a lower level - provides a relatively stable environment for buyers and sellers to agree valuations. Sale and purchase agreements relating to oil and gas assets are highly specialised, reflecting the unique nature and characteristics of the industry itself. This book, written by experienced and well-known practitioners from within the oil and gas industry, is intended to provide a practical review of the provisions typically included in such agreements. It aims to benefit lawyers and commercial negotiators working in the industry who handle sale and purchase transactions and who want to better understand the usual terms and conditions involved in those transactions. Legal professors and their students could also benefit from using the book as a teaching aid based on real-world experience.