Distributed ledger, also known as blockchain technology, or BT for short, is an Internet database technology, which is characterized by decentralization, openness and transparency, allowing everyone to keep records in a database. It is an emerging technology that has set off a wave of global investment after big data, cloud computing, artificial intelligence, etc. As the underlying technology of Bitcoin, blockchain technology is an Internet database technology which is essentially to record data and contracts along the time axis. This technology has already brought tremendous changes in finance, security and other fields, and is expected to do the same in the oil and gas industry. With oil and gas exploration and development undergoing digital transformation, blockchain technology is one of the most promising digital technologies.