鄂尔多斯盆地下寺湾油区延长组浅水三角洲沉积研究  

Study on shallow-water delta deposition in Yanchang Formation of Xiasiwan,Ordos Basin

作　　者：余逸凡[1] 戴胜群[1] 尹太举[1] 毛平[1] 董林[2] 

机构地区：[1]教育部油气资源与勘探技术重点实验室长江大学,湖北荆州434023 [2]中油辽河油田公司,辽宁盘锦124114

出　　处：《特种油气藏》2009年第5期28-31,共4页Special Oil & Gas Reservoirs

基　　金：中原油田公司创新项目"下寺湾油田合作区油气富集规律及沉积微相研究"(ZY-04-005)

摘　　要：鄂尔多斯盆地构造稳定,湖盆沉降速度缓慢,古地形平坦,气候干旱,湖泊面积相对较小,物源供给充足,在下寺湾油区形成了富有特色的浅水三角洲沉积。下寺湾油区浅水三角洲在骨架砂体类型、规模、形态等多方面与正常三角洲存在较大差别:平原相河道通过充填和频繁分叉汇合,向湖泊中心方向长距离推进;前缘广泛发育河道砂体,砂体呈带状分布,多个砂体垂向相互叠置,砂体厚度大,分布稳定;受可容纳空间限制和河道冲蚀作用,河口坝不发育;砂岩储层受河流控制作用明显,分叉与汇合现象普遍,砂体具有明显的方向性,砂体等厚图上呈朵状分布,砂体连通性较正常三角洲好。综合地形、气候、水动力条件等方面分析,确定了下寺湾油区各类砂体的成因及特征,并总结了下寺湾油区浅水三角洲沉积模式。Ordos Basin are characterized by stable structure,slow subsidence,flat palaeotopography,dry climate,small lake area,and sufficient material source,thus formed a distinctive shallow-water delta deposition in Xiasiwan oil province. Xiasiwan shallow-water delta is different from conventional delta in respects of framework sandbody,scale and shape. The channel of plain facies advanced a long distance to lake center through filling and frequent divaricating and flowing together. Channel sands were widely developed in the front,distributed in zonality,vertically superimposed,thick and stable. Mouth bar was not developed as restricted by accommodation and washing action. The sandstone reservoirs were obviously controlled by fluvial system. Divaricating and confluence are often seen. Sand bodies show obvious direction and lobe-like distribution on the isopach map. The connectivity of these sands is better than general deltas. The genesis and characteristics of various sands in Xiasiwan oil province are analyzed in respects of terrain,climate and hydrodynamic condition,and the deposition model is set up for the shallow-water delta in the study area.

关 键 词：浅水三角洲 分流河道 席状砂 沉积模式 下寺湾油区 鄂尔多斯盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探]