Abstract: Due to the large investment, less drilling, and difficulty to obtain data, the research of remaining oil in offshore is more difficult than land oil field. Aiming at the problem that C2 reservoir has the characteristics of high water cut, high recovery, and the highly dispersed of remaining oil. At the basis of seismic, drilling and logging data, the distribution of C2 remaining oil was forecast-ed by the application of the technology of geological, logging and reservoir engineering. By the research results of various methods, the remaining oil is most enriched in the north of C2 structure that was approved by adjusting well. And production and recovery of C2 reservoir was improved by adjusting well. The method is worthy of reference by the same kind reservoir in offshore.