Previous study shows that migration system is a major factor that controlled hydrocarbon migration and accumula-tion in Honghe oilfield in Ordos Basin.To better understand migration systems in the Yanchang Formation of this oilfield

we systematically analyzed the compatibility of the fault-sandbody assemblages in the field based on geological

mud logging and well logging

as well as seismic data of the area.A quantitative approach based on two indicators (the shale gouge ratio simplified as SGR and fault tightness index represented by I

FT

) was employed to study the transport capacity of faults in the study area.The results indicate that differential sealing behaviors between faults represent the differences of fault transport capacity.The effective migration-space coefficient(C

m

) and sand body transport coefficient(K

s

) were used to identify the main carrier beds and quantitatively analyzed their transport capacity.Study on the relationship between sandbody transport coefficients and oil and gas shows in the area revealed that sandbodies with K

s

>

2 have better transport capacity.A comparison between reservoir profiles of the key reservoiring period and present shows a good match between the area of oil and gas migration and accumulation and the distribution of nowadays reservoirs.The study indicates that the fault-sandbody assemblages were the main migration systems during the key reservoiring period of the low-porosity and permeability field (Honghe).It also points out that vertical migration along fractures was also possible in certain locations of the area.