鄂尔多斯盆地盐定地区长8时期物源分析  

Analysis of Sediment Provenance of Chang8 Group of Yanchang Formationin Yanchi-Dingbian Area of Ordos Basin

作　　者：庄一鹏[1] 郭西峰 付斌[1] 

机构地区：[1]西安石油大学油气资源学院,陕西西安710065 [2]长庆油田公司第三采油厂地质研究所,宁夏银川750004

出　　处：《西北地质》2011年第2期133-140,共8页Northwestern Geology

基　　金：中石油天然气股份有限公司长庆油田分公司"盐定地区延长组超低渗油藏增储建产目标区优选"(00104104)

摘　　要：鄂尔多斯盆地西部盐池—定边地区延长组长8时期沉积特征多变,区内物源、沉积体系等系统研究程度较低,给该地区油气的进一步勘探开发带来了一定的不利影响。为探明其物源状况,揭示该地区沉积体系的分布格局,通过常规矿物成分、重矿物、岩屑和地球化学特征等多种研究方法,对盐定地区的物源及源区母岩性质等进行了系统分析。结果表明,研究区碎屑组分、重矿物具有较明显的分区性,结合岩屑分布特征、稀土元素特征,认为该地区主要受到3个方向物源控制,即西北、北部和东北部,其中西北和北部物源是控制区内沉积的最主要物源。古物源与沉积体系空间配置关系良好,并从根本上决定了长8时期的沉积体系分布格局以及砂体展布方向,对油气的运、聚起到一定的控制作用。In the west part of Ordos basin,the sedimentary characteristics of Chang-8 formation in Yanchi-Dingbian area vary a lot.However,the provenance and depositional system are not well studied,having an unfavorable effect on further exploration.In order to verify the provenance and depositional system distribution,we analyze the characteristics of the mother rocks in the source by studying the mineral composition,heavy mineral,debris and geochemical characteristics.The results indicate that there is an obvious partition in both detrital component and heavy mineral.Integrating the debris distribution and rare-earth element features,we conclude that this area is mainly controlled by provenance from three major directions： northwest,north,and northeast,among which the provenance from the northwest and the north are the most primary ones.Palaeo-provenance match well with the depositional system in space,thus radically determines the depositional system pattern of the Chang-8 （Member 6 of Yanchang Formation） and distribution of sand body,which contribute a lot to oil migration and accumulation.

关 键 词：物源分析 鄂尔多斯盆地 盐定地区 长8油层组 沉积体系 

分 类 号：TE132.1[石油与天然气工程—油气勘探]