Abstract: This article introduced an new petroleum technology in the world which is called smart well. As one new completion technique, it provides petroleum resources with a kind of more intellectual and flexible management, so it gains more and more attention. Some specialists abroad ever indicate that today's petroleum should use intellectual technology extensively to carry out underground supervision and attendance. There are also some people who call smart well as down hole permanent monitoring system, it can not only realize simultaneous production from multilayer, but also can produce solely from one layer with the ability of collection, transmission and analysis of borehole production data, reservoir data and well completion generated data, and improve reservoir performance and production performance by long-range control. Nowadays, smart well technique has been applied to horizontal well, offset well, multi-lateral well, remote area and subsea operation and also to production well and injection well.