Abstract: Caofeidian oilfield is a fluvial facies and low oil column reservoir with edge water in Bohai Bay area. It has been developed by horizontal wells for10years, and now its edge water has become secondary bottom water in it, which puts forward higher requirement for late?stage development by horizontal well in terms of water?avoidance height. This paper identifies the abandoned channels in area with a few wells by using the data of directional wells and horizontal wells, predicts them by means of flattening the sand top height in area with no well, and presents the depiction of the internal sand bodies in single channel and draws the plan of sedimentary microfacies. Based on the abandoned channel outcrop in meandering river, the impact of layer position encountered by horizontal well on its water?avoidance height is analyzed for the purpose of guiding the accurate landing design of adjustment wells and providing the basis for comprehensive adjustment plan’s implementation of horizontal wells in Caofeidian oilfield in the future