Reservoir Evaluationg Of The Lower Bench Of Yan Chang Group In Qiaogouwan Xihekou Region Of Ordos Basin

The paper take the oil layers in lower bench of Chang7-Chang10of Yan Chang group in Qiaogouwan-Xihekou Region of Ordos Basin. Utilize geology of petroleum、sedimentology、 reservoir geology and statistics to analysis and research, according to the analysis of numerous of thin slices, image pores, scanning mirror, mercury penetration and physical property materials, we study the reservoir quality. In research area, chang10oil bearing group is snaking stream sedimentary system、chang9oil bearing group is meare sedimentary system, chang8oil bearing group mainly is delta leading edge sedimentary system、chang7is lacustrine deposit, framework sand body is under water distributary channel.From the research, we knew the lithologic of the lower bench of Yan Chang group is fine grain lithic arkose、arkosic arenite and feldspar lithic sandstone, interstitial material is consists of clay mineral、carbonate crbn、secondary origin quartz and secondary origin feldspar adglutinate, hole style cementation, intergranular pore is primarily, pore types are fine pore-slim throat and slim pore-tiny slim throat; while denudation of feldspar and adelforsit and the formation of micro-fracture are main factor to change reservoir physical property. The secondary pore close to fracture makes up the chief reserving space of oil and gas and the low permeable reservoir and extremely low permeable reservoir predominated.Reservoir type mainly is up-bear and down-storage, organic collocation of reminder differential pressure and fractured is favour of storage of lower interval. By study the exhibition of oil-bering series reservoir sand body、reservoir characteristic、the development of hydrocarbon rock and association characteristic of oil-generating strata、reservoir and capping formation in research area, refer to development performance, forecast correlation profitability areas.