鄂尔多斯盆地志靖安塞地区长9油层组沉积相及其沉积演化特征  

Sedimentary facies and evolution of Chang 9 oil formation in Yanchang Formation, Zhijing-Ansai area,Ordos Basin

作　　者：张三[1,2] 杨博 李廷艳[1,2] 王慧玲[1,2] 张振红[1,2] 汪伶俐[1,2] 

机构地区：[1]低渗透油气田勘探开发国家工程实验室,陕西西安710018 [2]中国石油长庆油田分公司勘探开发研究院,陕西西安710018 [3]中国石油长庆油田分公司第十一采油厂,甘肃庆阳745000

出　　处：《地质通报》2015年第10期1964-1970,共7页Geological Bulletin of China

基　　金：中国石油天然气股份公司重大科技专项(编号:2011E-2602)

摘　　要：志靖安塞地区位于鄂尔多斯盆地陕北斜坡中部。以钻井取心观察为基础,结合砂岩厚度、砂地比、自生绿泥石分布、古生物化石分布等因素,对长9油层组2个层段沉积相空间展布特征及沉积演化规律进行研究。结果表明,长9油层组发育一套三角洲-湖泊沉积,北部主要发育三角洲前缘沉积,在南部发育浅湖沉积。长92沉积期,湖盆范围较小,长91沉积期湖盆初始扩张,湖岸线向北推进,湖域面积增大。从长92沉积期到长91沉积期,研究区经历了沉积水体由浅变深的过程,并在长91顶部发育一套具有生烃潜力的高阻泥岩。三角洲前缘水下分流河道砂体是较有利的储集砂体。Zhijing-Ansai area is located in the middle of Shanbei slope of the Ordos Basin. Based on detailed observations of well core, sandstone thickness, sandstone strata thickness ratio, authigenic chlorite development characteristics, and paleontological characteristics, the authors studied the distribution regularity of sedimentary facies and the sedimentary evolution. The results show that a suite of meandering fluvial deltas-lacustrine sediments were developed in the study area. The delta front deposits were mainly developed in the northern part of the study area, whereas shallow lake sediments were developed in the southern part of the study area. The size of the lake basin in Chang 92 oil formation was smaller than that in Chang 91 oil formation. During the depositional period of Chang 91 oil formation, the lacustrine basin began to expand, and lake shoreline moved to the land, with the expansion of the lake area. Form Chang 92 oil formation to Chang 91 oil formation, the water depth changed from shallow to deep, and then a set of high resistance mudstones with hydrocarbon-generating potential were deposited, and the deltaic front subaqueous distributary channel sand bodies became high quality reservoirs.

关 键 词：沉积相 长9油层组 延长组 志靖—安塞地区 鄂尔多斯盆地 

分 类 号：P618.13[天文地球—矿床学]