鄂尔多斯盆地东南部的富县、 黄龙一带长8油层组勘探程度较低, 勘探潜力不明. 依据钻井、 测井、 分析化验等资料,从烃源岩条件、 储集条件和成藏模式3个方面探讨了研究区长8油层组的勘探潜力. 结果表明, 研究区发育长7油层组底部和长9油层组顶部两套烃源岩, 其中长7油层组底部烃源岩为主力烃源岩, 其有机质丰度高, 处于生油高峰阶段, 两套烃源岩总地质资源量约为3. 43×108t; 三角洲前缘水下分流河道的叠置砂体为主要储集体, 岩性以细粒长石砂岩为主, 为特低孔隙度、 特低渗透率储层, 主要储集空间为残余原生粒间孔和次生孔隙; 为双向排烃、 复合成藏模式. 优质储层及烃源岩条件为成藏主控因素, 预测有利勘探潜力区面积约为446. 5km2.%Exploration breakthroughs have been increasingly made in Chang 8 pay zone of Triassic Yanchang Formation in mid-western Ordos Basin in recent years, and Chang 8 pay zone thus becomes a replacement layer of powerful strategic re-sources for sustained and stable growth of oil reserves. But the exploratory level of Chang 8 pay zone is still low in Fuxian and Huanglong areas southeast of the Basin. Based on laboratory analysis, drilling and logging data, exploration potential of Chang 8 pay zone is discussed from source rock conditions, reservoir conditions and reservoir forming patterns. The research results show that there are two sets of source rocks at the bottom of Chang 7 and the top of Chang 9 in study area and the former gives first place and is high in organic matter abundance and still in the oil generating peak stage. Total reserves of the two sets of source rocks are about 3. 43×108t. Overriding sand bodies of underwater distributary channel in delta front are the chief reservoir, and lithology is dominated by fine grained feldspar sandstone of ultralow porosity and ultralow per-meability. Reservoir space is residual intergrannular pore and dissolved pore, and reservoir forming patterns are bidirection-al expulsion, with composite reservoir model. With the high quality reservoir and the source rock condition to be the main controlling factor of reservoir forming, the acreage of the area with great exploration potential is about 446. 5km2 .
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