鄂尔多斯盆地三叠系延长组长7油层组油页岩沉积环境与资源潜力研究

Research on the Depositional Environment and Resources Potential of the Oil Shale in the Chang 7 Member,Triassic Yanchang Formation in the Ordos Basin

鄂尔多斯盆地三叠系延长组长7油层组油页岩，主要分布在盆地南部，单层厚度15-30m（最厚处超过40m），含油率5％～10％。延长组沉积时是鄂尔多斯盆地发育的鼎盛时期，长7期湖盆范围达到最大。通过对长7油页岩分布与沉积相展布关系的研究，认为鄂尔多斯盆地油页岩的分布受沉积环境的控制作用显著，深湖一半深湖相沉积环境下形成的油页岩，具有含油率高、厚度大和分布范围广的特点。长7油页岩资源丰富，油页岩资源量为10476亿t，而且盆地构造相对简单，开发条件优越。因此，鄂尔多斯盆地长7油页岩具有广阔的勘探开发前景。

The Chang 7 member of the Triassic Yanchang Formation in the Ordos Basin contains wealthy of oil shale resources. It is mostly distributed in the southern part of the basin and the thickness of these layers is from 15 to 30 meters （with the thickest exceeds 40 meters） with 5% to 10% oil yield. The development of the Ordos Basin reached its culmination in the sedimentary period of the Yanchang Formation and the lake basin was largest in area during the Chang 7 epoch. Based on the research on the relationship between the distribution of oil shale and the character of sedimentary facies during Chang 7 epoch, we suggest that the distribution of oil shale is remarkably controlled by the depositional environment then. The oil shale of the Chang 7 member formed under deep lake to half deep lake environment are of higher oil yield and of thicker and wider distribution range. The Chang 7 member in the Ordos Basin is very rich in oil shale resource and the volume of the shale oil resources is 10 476×10^8t. Moreover, because the structure of the Ordos Basin is simple, their exploitation conditions are good. So the Chang 7 member of the Yanchang Formation in the Ordos Basin is potential for prospecting and exploitation.