Microscopic pore structure characteristics of Yanchang formation in south of Ordos basin

Through statistics and analysis of typical pore structure characteristic parameters from84 wells of Yanchang formation in the south of Ordos basin,the relationship between physical properties and oil displacement efficiency has been discussed.The results showed that the expulsion pressure and median pressure has negative correlation with the physical properties,while the median radius,average throat diameter and sorting coefficient has positive correlation with the physical properties.The pore structure coefficient,homogeneous coefficient and physical properties have no correlation,while there is a certain correlation between oil displacement efficiency and pore structure parameters.Generally speaking,the effect of pore structure on oil displacement mechanism is more complex,rather than the simple linear relationship.