Influence of reservoir bed heterogeneity on hydrocarbon accumulation: Taking beach-bar sandstone of upper fourth member of Eocene Shahejie Formation in Boxing oilfield as an example

Based on the analyses of logging data and experiment, it is discussed in this paper the reservoir bed heterogeneity and its effects on hydrocarbon accumulation in the upper fourth member of Eocene Shahejie Formation of the Boxing oilfield. The result shows that the beach-bar reservoir bed with thin interbedded sandstone has strong heterogeneity. Hydrocarbon distribution and property are extremely uneven. Influenced by diagenesis, beach-bar sandstone shows strong heterogeneity, leading to different reservoir bed qualities in different areas. Reservoir bed quality has a good correspondence with hydrocarbon-bearing property, and reservoir bed heterogeneity controls the accumulation and distribution of hydrocarbon as well as oil saturation. Simulated experiment indicates that the relationship between driving force and resistance has effects on hydrocarbon accumulation feature and weakens the control of hydrocarbon accumulation by reservoir bed heterogeneity to a specific extent.