鄂尔多斯盆地中部山西组三角洲—曲流河沉积  

Evidences of fluvial deposition of Shanxi formation in central Ordos Basin

作　　者：郝爱武[1,2] 蒲仁海[1] 郭向东 

机构地区：[1]西北大学地质学系/大陆动力学国家重点实验室,陕西西安710069 [2]陕西延长石油集团,陕西延安716000

出　　处：《西北大学学报（自然科学版）》2011年第3期480-484,共5页Journal of Northwest University（Natural Science Edition）

基　　金：国家重大专项大型岩性油气田与煤层气开发基金资助项目5(2008ZX05001-003);延长石油集团勘探基金资助项目(2008字115号)

摘　　要：目的探讨山西组汇水中心有无曲流河沉积。方法通过岩心观察、测井对比、三维地震综合解释等分析鄂尔多斯盆地中部山西组沉积相。结果大量的砂岩底部冲刷、心滩加积式和边滩退积式测井响应反映盆地中部三延地区山西组二段和一段可能为两个湖泊—三角洲—河流相旋回沉积,湖泊具多期小规模发育特点,三角洲前缘和河道砂体类型同时发育,是该区的主要储层类型。结论三延地区虽然是鄂尔多斯盆地的汇水中心,存在南北物源的三角洲沉积,但是三维地震平面图显示出了典型的曲流河道特征。Aim To probe if meandering fiver exists in the catchment center of Shanxi Formation. Methods Associated with previous study results, well core, log and 3-D seismic data are integrated to probe whether fluvial deposition of Shanxi Formation exists in central Ordos basin which is considered to be an ancient large lake center. Resuits Shanxi Formation consists of two mid-term baselevel cycles of lacustrine-deltaic frontier-fluvial deposition. Lakes might occur to a small scale in the central area of the basin during several periods, where both deltaic and fluvial sandbodies distributed simultaneously. They are the main types of the gas reservoir in this region. Conclusion 3-D seismic horizon slices show classical meandering channel distribution of Shanxi Formation. It should be an irrefutable evidence of fluvial deposition.

关 键 词：汇水中心 古流向 曲流河 三角洲前缘 砂体展布 

分 类 号：P618.130[天文地球—矿床学] TE122.2[天文地球—地质学]