Based on the massive analytical data of core

we comprehensively researched on the main controlling factors of the tight oil reservoir according to the property and the storage space of the tight oil formation in Chang-8 reservoir of Fu County in Ordos Basin. Fine sandstone in Chang-8 reservoir contained the movable tight oil with low density and low viscosity

and mostly concentrated in micron-sized pore throats. The accumulation of tight oil was mainly controlled by three factors that were the source rocks of Chang-7 and Chang-9 reservoirs

the main accumulation mode of

"

the reservoir existed in the resource

and the resource existed in the reservoir

"

and the high quality reservoir with composite superimposed sedimentary sand body formed in the underwater distributary channel microfacies environment. Based on the contr

olling factors above

and combined with the current exploration results

we predicted 6 potential blocks of Chang-8 tight oil reservoir in Fu County

and provided the basis for the further exploration.