The Characteristic Of Chang8Reservior In Yanchang Formation In Zhiluo Oilfield, Ordos Basin

This article is based on the Chang8reservoir characteristics of Yanchang in Late Triassic which belongs to the Zhiluo oilfield in Ordos basin. It comprehensively evaluates the sedimentary facies, the reservoir characteristics, diagenesis, physical property, the pore structure and the influence factors of the reservoir. Then, it forecast the favorable exploration target zone.Chang8in Zhiluo oilfield belongs to delta depositional system, mainly develops delta front sub-facies. And underwater distributary channel is the most favorable micro-facies. Chang8reservoir of Yanchang formation is divided into two oil sub-groups:Chang81and Chang82. The source of the research area is from northeast and southwest. It belongs to the mix source sedimentary zones. The lithology of the reservoir is mainly fine-middle grain of lithic greywacke and feldspathic litharenite. Chang8belongs to low and extra-low permeable reservoir. The pore structure is mainly dissolved pore-intergranular pore and intergranular pore-dissolved pore. Based ong the lithologic and poroperm characteristics, the Chang8is divided into three types. In combination with regional geological background, sedimentary evolution characteristics of Yanchang formation, the rock type, lithology, sedimentary structure, logging and profile structure characteristics, it concludes that favorable zone of Chang82reservior exists Fuxi2and Zi30well, favorable zone of Chang81reservior exists Lu46and Zi9well.