Abstract: Hangjinqi area is an important hydrocarbon bearing area in the north of Ordos basin. The study of petroleum accumulation periods and fluid potential is conducive to exploring the generation of petroleum filling, the distribution characteristics of fluid potential, and further determining the migration direction of oil and gas during the accumulation period. In this paper, the reservoir sandstones of the First Member of Xiashihezi Formation (He 1) of the Permian system in five wells of Shiguhao block and Shilijiahan block are taken as the research objects. Based on the fluid inclusion analysis, the petroleum accumulation periods are determined, the fluid potential of the key reservoir formation periods in the study area is calculated, and the migration direction of petroleum is revealed by combining the fluid potential theory. The research results showed that the petroleum accumulation time of He 1 Member reservoir was 132-102 Ma in Shiguhao area, and 132-101 Ma in Shilijiahan area. The fluid potential of petroleum in He 1 Member of Shiguhao area in the north of Hangjinqi is 18 128-22 872 J/kg, and of Shilijiahan area in the south of Hangjinqi is 22 975-27 153 J / kg. It is considered that hydrocarbon accumulation time of the Permian He 1 Member reservoir was in the Early Cretaceous. The overall fluid potential in Shilijiahan area is higher than in Shiguhao area, and the petroleum has a migration trend from south to north.

Key words: fluid inclusion, petroleum accumulation time, fluid potential, hydrocarbon migration, reservoir, Hangjinqi area, Ordos basin