3D and 4D (or time-lapse) seismics are techniques commonly used for exploration and reservoir exploitation. Increasingly, time-lapse seismic is becoming a more popular tool for reservoir development and management. However, its application is constrained by reservoir conditions, production mechanisms and seismic data repeatability. The technique of 3D exploration for remaining oil with historical production data (called a 3.5D seismic approach to differentiate it from time-lapse seismic) uses high quality 3D seismic data, acquired after a certain period of reservoir production, and integrates them with historical production data to provide information for reservoir dynamics, such as the identification of additional resources and the delineation of remaining oil. In integrating the 3D seismic with historical production data, the 3D seismic data are time-stamped and then related to the reservoir dynamics. This enables 3D seismic data to represent reservoir dynamics in time. In this paper we present a case study in an onshore mature oil field in western China, where no baseline 3D seismic survey is available, with production data spanning a period of 16 years from 1990 to 2006, and with a 3D seismic survey acquired in 2006. The results show that the 3.5D seismic approach can identify reservoir potential and remaining oil.