Abstract: Located in the urban area of Daqing city,Sazhong oilfield is characterized by thick oil layers,multi-layered co-development,dense well spacing and too many surface buildings,which provides a series of problems for well location design in secondary development.In order to solve these problems,the principles in secondary development of Sazhong oilfield have been worked out,that all well patterns will be designed to the extreme in one time,the drilling and the accessory structure on ground of the development will be accomplished in one time.The reservoir well locations have been optimized individually,and a series of methods have been developed to optimize well locations on ground.In the end,the methods for well location optimization and implementation of secondary development in urban area oilfield have been established,which achieves good implementation effect and provides reference for similar oilfields of secondary development.