Blockchain, also known as distributed ledger technology, is a simple technology construct but with far-reaching impacts, and it is coming quickly to oil and gas. Blockchain combines encryption, distributed computing, decentralized architecture and cloud computing in a novel way to create new business models that do not require trust between counter parties. Blockchain is thus poised to overhaul legacy ways of working in oil and gas that involve assets, ownership, identity, money, contracts and of course, trust. Beyond transformation of business processes (both operational and commercial), blockchain combines with other technologies such as the internet of things, artificial intelligence and automation in more profound ways to create fundamentally different business models. For example, blockchain and artificial intelligence working together on a powered device allows that device to purchase and settle power purchases based not just on load but the price of power. Early use cases of relevance to oil and gas include commodity trading, asset tracking, royalty and venture accounting, but other examples in areas as diverse as shipping, financial transactions, used equipment trading and of course, currency, also underscore the profound possibilities presented by this technology set.