鄂尔多斯盆地西南部延长组长8油层组储层特征及其影响因素分析

发布时间：2018-04-15 22:09

本文选题：鄂尔多斯盆地西南部 + 长8油层组　；参考：《西北大学》2015年硕士论文

【摘要】：鄂尔多斯盆地油气资源分布非常广泛。延长组长8油层组是主要的目的层段之一。本文以盆地西南部的上里塬、合水、西峰和马岭四个区块为主要研究对象,综合利用铸体薄片、扫描电镜、岩心观察、X衍射、高压压汞等技术手段,在广泛收集整理前人研究的基础上,对盆地西南部延长组长8油层组的岩石学特征、物源、沉积微相、孔隙结构、成岩作用以及构造活动等进行了系统研究,总结了储层物性的影响因素以及优质储层的形成条件。研究区位于鄂尔多斯西南部,物源方向主要为西南向,盆地内的沉积演化严格受沉积相带的控制,沉积作用是决定储层物性的基础。研究区整体发育一套湖泊背景下的三角洲前缘亚相沉积体系。碎屑物粒度较细,多为细砂岩,岩性以长石岩屑砂岩为主,填隙物种类丰富。储层孔隙度、渗透率均较低,其中西峰地区相对高孔高渗。成岩作用和构造作用对沉积物进行了强烈的后期改造。压实作用使原生粒间孔隙缩小为残余粒间孔；胶结物充填于孔隙,占据储集空间,使储层物性变坏。溶蚀作用产生大量次生孔隙,是研究区内重要的建设性成岩作用。通过研究认为研究区内储层特征主要受沉积作用、成岩演化和构造活动的共同控制,优质储层的发育同样受三者的综合影响。
[Abstract]:Oil and gas resources are widely distributed in Ordos Basin.Yanchang formation 8 is one of the main target formations.In this paper, the four blocks of Shangliyuan, Heshui, Xifeng and Maling in the southwest of the basin are taken as the main research objects. The techniques of casting thin slice, scanning electron microscope, core observation X-ray diffraction and high pressure mercury injection are used synthetically.On the basis of extensive collection and collation of previous studies, the petrological characteristics, provenance, sedimentary microfacies, pore structure, diagenesis and tectonic activity of the Yanchang formation 8 in the southwest of the basin are systematically studied.The influencing factors of reservoir physical properties and the formation conditions of high quality reservoirs are summarized.The study area is located in the southwest of Ordos, and the direction of the source is mainly southwest. The sedimentary evolution in the basin is strictly controlled by the sedimentary facies belt, and the sedimentary process is the basis of determining the reservoir physical properties.A set of delta front subfacies sedimentary system is developed in the study area.The grain size of clastic material is fine, mostly fine sandstone, the lithology is dominated by feldspathic lithic sandstone, and the types of interstitial materials are abundant.The porosity and permeability of reservoir are all low, and Xifeng area is relatively high porosity and high permeability.Diagenesis and tectonism made a strong late transformation of sediments.Compaction reduces the primary intergranular pore to a residual intergranular pore, while the cement fills the pore, occupies the reservoir space, and makes the reservoir physical property worse.Dissolution produces a large number of secondary pores, which is an important constructive diagenesis in the study area.It is considered that the reservoir characteristics in the study area are mainly controlled by sedimentation, diagenetic evolution and tectonic activity, and the development of high quality reservoirs is also affected by the three factors.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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