Abstract: Shuanghe oilfield has been in late stage of development with high water cut, therefore, it is highly urgent to determine the direction of geological study. This paper reviews the history of study of development geology, points out that development geological study must focuses on the producing targets, and summarizes the distribution characteristics of the remaining oil. The following geologic studies should be carried out in the future:identifying small layers with remaining oil in watered out region through fine division of thin single layers; understanding the 3D characteristics of the remaining oil through strengthening fundamental research; speeding up computerization of fine reservoir characterization and putting them into field application as soon as possible; activelystudying on ways to tap the remaining production potentials to enhance waterflooding recovery factor of the mature oilfield. The production capacity of mature oilfields can be maintained only when all the fundamental works are to be carried out according to the law of oilfield production.