鄂尔多斯盆地安塞地区长7段页岩油资源潜力评价

SHALE OIL RESOURCES ASSESSMENT FOR THE MEMBER CHANG 7 IN ANSAI AREA OF ORDOS BASIN

鄂尔多斯盆地安塞地区三叠系延长组长7段油页岩在西南部较为发育,厚度可达到10m以上,氯仿沥青"A"平均值达到0.87%,具备形成页岩油的地质基础。利用CT扫描电镜技术、核磁共振等技术对长7段油页岩储集空间及储集性能进行定量表征,揭示纳米级黏土颗粒片状孔隙是长7段页岩油的主要孔隙类型,平均有效孔隙度4.86%,平均含油饱和度为44.63%。安塞地区长7段具有页岩油赋存与聚集成藏的物质基础,大规模分布的黑色油页岩、良好的储集空间和充足的烃类,原油黏度低、油页岩可压裂性好、高角度裂缝发育等有利于页岩油在纳米级孔喉中流动和开采,预测资源潜力达到4.42×10~8 m^3,并指出了水平井+体积压裂提高单井产量的攻关方向。

The oil shale of the Chang 7 Member of the Triassic Yanchang Formation in the Ordos Basin mainly occur in the southwest Ansai area,with a thickness of more than 10 meters.The average content of chloroform asphalt'A'reaches 0.87%,that found the basis for shale oil formation.CT SEM,NMR and other techniques have been used to quantitatively characterize the storage space and storage performance of the oil shale.It’s revealed that the nano-sized clay granules flake pores are the main types of pores for shale oil storage.The average effective porosity approaches 4.86%and the average oil saturation 44.63%.The Chang 7 Member of the Ansai area has provided excellent material basis for shale oil accumulation.There are great amount of and widely distributed black oil shale,sufficient hydrocarbon,low viscosity of crude oil,excellent high-angle fracture system and reservoir space,all of which are beneficial to the oil flowing through the nanoscale pore throat.Resource assessment suggests that a resource potential of 4.42×10~8 m^3 is expected.Using horizontal well and volume fracturing,single-well production will be improved.