中文摘要：

鄂尔多斯盆地为大型富含油气盆地，发育本溪组、山西组、延长组长7段、长9段等多套页岩层系，具备页岩气形成的基本地质条件。为查明鄂尔多斯盆地东南部延长组长7段页岩气的勘探潜力．本文利用有机地球化学和岩石学分析、含气量测试、等温吸附曲线测定等多种手段，分析了延长组长7段页岩的基本地质、地化及含气性特征。在此基础上．对长7段页岩气勘探潜力进行了初步评价。结果表明，长7段陆相页岩埋深和厚度适中、有机质类型以I、Ⅱ型为主，有机质丰度和脆性矿物含量高，含气量可达1．25～6．45ml／g。与北美地区典型页岩相比，研究区长7段页岩有机质类型、有机碳含量类似，粘土矿物含量和长石含量偏高．碳酸盐和石英含量偏少，有机质成熟度偏低。研究区内延长组长7段页岩气资源勘探潜力巨大．资源量为1528．409亿m^3．可作为常规油气勘探的重要补充，志丹-甘泉-线西南部为页岩气勘探的有利目标。

英文摘要：

As a large-sized petroliferous basin with many shale formations such as Benxi Formation, Shanxi Formation, and 7th and 9th member of Yanchang Formation, the Ordos basin has the basic geological conditions for shale gas development. In order to evaluate the shale gas exploration potential of 7th member of Yanchang Formation, the authors investigated the geological and geochemical characteristics of 7th member shale with the aid of organic geochemical and petrologic analysis, gas quantity test and isothermal adsorption curve test. On such a basis, the preliminary evaluation of 7th member shale gas exploration potential was carried out. The results show that the shale of 7th member has moderate burial depth and thickness. With high abundance of organic matters which are mainly of I - IT type, the maximum gas quantity could be up to 1.25-6.45 ml/g. The kerogen type and TOC of the 7th member shale are similar to those of marine shales in North America. Compared with marine shales in North America, the 7th member shale has higher content of feldspar and clay minerals but lower content of quartz and carbonate content as well as lower maturity. The shale gas exploration potential in the study area is quite promising and could serve as an important supplement of conventional exploration. The favorable targets lie in the southwest of Zhidan-Ganquan area.