马海东构造带下干柴沟组下段高分辨率层序地层和砂体展布特征

发布时间：2018-02-25 20:25

本文关键词： 高分辨率层序地层层序界面识别中期旋回砂体展布下干柴沟组马海东构造带古近系柴达木盆地青海省　出处：《地层学杂志》2017年01期 　论文类型：期刊论文

【摘要】：以高分辨率层序地层学和沉积学理论为指导,通过综合运用地震、测录井、岩芯等资料,对马海东构造带古近系下干柴沟组下段进行了高分辨率层序地层学研究。研究区共识别出不同规模的层序界面共6种类型,包括角度不整合、大规模冲刷面、中等规模冲刷面、小型河道下切面、地层样式转换面和沉积环境转换面。在层序界面识别的基础上,将目的层段划分为1个长期基准面旋回(LSC1)、3个中期基准面旋回(MSC1-MSC3)和12个短期基准面旋回(SSC1-SSC12),其中MSC2发育低可容纳空间向上"变深"非对称型(A1)旋回结构,MSC1、MSC3发育高可容纳空间向上"变深"非对称型(A2)旋回结构。建立了研究区层序地层等时对比格架,探讨了各中期层序沉积微相特征和砂体展布规律,结果表明,MSC2中期旋回内发育辫状河道心滩沉积微相,沉积物以砂砾岩、含砾粗砂岩、中细砂岩为主,砂体垂向厚层叠置,横向广泛连通,为研究区最为有利砂体发育层段。
[Abstract]:Guided by the theory of high-resolution sequence stratigraphy and sedimentology, and through the comprehensive application of seismic, logging, core and other data, A high resolution sequence stratigraphy study on the lower member of Lower Ganchaigou formation of Paleogene in the Mahaidong tectonic belt has been carried out. Six types of sequence interfaces of different sizes have been identified in the study area, including angular unconformity, large-scale scour surface, medium scale scour surface, etc. On the basis of the recognition of sequence interface, the subsurface of small river channel, the transformation surface of formation style and the transformation surface of sedimentary environment. The target layer is divided into 1 long-term base-level cycle (LSC1), 3 medium term base-level cycles (MSC1-MSC3) and 12 short-term base-level cycles (SSC1-SSC12), in which the MSC2 is low in development and can accommodate the upward "depth" asymmetric A1) gyratory structure of MSC1MSC3 with high capacity. The upward "varying depth" asymmetrical type A _ 2) cyclic structure of the nanospace has been established. The isochronous frame of sequence stratigraphy in the studied area has been established. The characteristics of sedimentary microfacies and the distribution of sand bodies are discussed. The results show that the sedimentary microfacies of braided channel core beach are developed in the middle period of MSC2 cycle. The sediments are composed of sandy gravel, gravelly coarse sandstone, medium fine sandstone and vertical thick sand body superimposed. The horizontal connection is the most favorable section for the development of sand bodies in the study area.
【作者单位】：中国石油大学(华东)地球科学与技术学院;中石化胜利油田分公司西部新区研究院;
【基金】：中国石油大学(华东)与胜利油田西部中心研究课题“马海东构造带古近系沉积特征研究”资助
【分类号】：P618.13;P539.2

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