Major controlling factors of reservoiring in the upper 4th member of Shahejie Fm in Yangxin depression

Based on study of the structural and stratigraphic features of Yangxin depression, oil/gas reservoiring characteristics are analyzed in respects hydrocarbon sources, reservoir characteristics, combination of cap rock and reservoir rock, as well as reservoir types. Oil/gas reservoiring and distribution are mainly controlled by hydrocarbon sources, direction of hydrocarbon migration, structure and lithology. The abundant hydrocarbon source in the upper 4th member of Shahejie Fm is an important factor controlling oil/gas enrichment. Hydrocarbon migration is characterized by intraformational lateral migration. Traps located in the direction of hydrocarbon migration are favorable for reservoiring. Large anticlinal and faulted-nose structures are the main sites for oil-gas accumulation, and oil-gas distribution are controlled by structure and lithology.