鄂尔多斯盆地东南部山2段物源与曲流河三角洲沉积体系

发布时间：2018-03-17 04:33

本文选题：曲流河三角洲　切入点：物源　出处：《沉积学报》2017年03期 　论文类型：期刊论文

【摘要】：鄂尔多斯盆地东南部山2段是该盆地重要的天然气富集层位。通过重矿物分布、岩屑组分、砂岩岩屑类型及阴极发光特征分析山2段沉积物源体系,经研究认为盆地东南部山2段沉积同时受南、北部物源供源。山2段为曲流河三角洲前缘沉积亚相,碎屑颗粒分选中等偏好、磨圆较好、颗粒之间接触紧密,沉积构造主要为板、槽状交错层理、平行层理及浪成交错层理。本区山2段沉积物以跳跃组分和悬浮组分为主,水下分流河道微相粒度概率曲线呈现三段式和四段式;河口坝微相分选较好、粒度概率曲线形态为两段式和三段式。研究区北部、南部及中部志丹、甘泉等地区砂体发育较厚,剖面上河道砂体呈不对称式相互叠置,水动力条件中等—较强。通过物源体系重建、沉积特征分析与薄片特征鉴定,建立了鄂尔多斯盆地东南部山2段双物源曲流河三角洲沉积模式。该研究明确了盆地东南部山2段物源方向,明晰了山2段沉积特征,创建了典型曲流河三角洲沉积模式,为进一步勘探开发提供了理论支持。
[Abstract]:Shan2 formation in the southeast of Ordos Basin is an important natural gas enrichment horizon in this basin. The sediment source system of Shan 2 member is analyzed by heavy mineral distribution, lithic composition, sandstone lithic type and cathodoluminescence characteristics. It is considered that the sediments of the second member of Shan 2 in the southeastern part of the basin are simultaneously supplied from the south and the north. The second member of the basin is a sedimentary subfacies in the front edge of the meandering river delta. The clastic grains have a medium preference for sorting, and the grinding circles are better, and the contact between the particles is close. The sedimentary structure mainly consists of plate, trough interlaced bedding, parallel bedding and wave-formed interlaced bedding. The sediment of the second member of mountain in this area is mainly composed of jumping component and suspended component, and the probability curve of microfacies granularity of underwater distributary channel presents three and four sections. Estuarine dam microfacies separation is better, the shape of granularity probability curve is two-section and three-section. Sand bodies in the northern, southern and central areas of the study area, such as Zhidan and Ganquan, are relatively thick, and the channel sand bodies on the section are asymmetrically overlapped with each other. The hydrodynamic condition is medium to strong. Through the reconstruction of the source system, the analysis of sedimentary characteristics and the identification of sheet characteristics, The depositional model of double source meandering river deltas in the southeastern part of Ordos basin is established, the direction of material source of the second member of the southeastern part of the Ordos basin is determined, the sedimentary characteristics of the second member of the basin are clarified, and the typical sedimentary model of meandering river delta is established. It provides theoretical support for further exploration and development.
【作者单位】：中国地质大学(北京)能源学院;陕西延长石油(集团)有限责任公司研究院;
【基金】：国家自然科学基金项目(41472091)~~
【分类号】：P512.2

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