Abstract: Index of Grains with Oil Inclusion indicates the richness of fluid inclusions in the rocks and its values and characteristics can be used to show the history of oil and gas migration and accumulation, which helps to delimit the most extension of oil and gas migration on the plan and the section in a area. In this paper, the definition of GOI has been introduced, and then the principle and the criterion as well as the operation process utilizing GOI delimiting the oil and gas migrating scope have been presented. The application on the Binbei area in Songliao basin showed that the oil and gas migration range of shallow accumulation assemblage in Binbei area mostly covered 20000km2 closed to the Binzhou railroad on the plan and the range of it mostly extends between 1500m and 2000m on the section. The oil and gas shows and the law of oil and gas distribution controlled by hydrocarbon source rocks confirmed the results.

Key words: GOI, fluid inclusion, migration scope, Songliao Ｂasin, Binbei area