致密储层非均质性对油气成藏的影响研究

发布时间：2018-07-11 21:38

本文选题：岩性油气藏 + 三角洲前缘亚相　；参考：《长江大学》2017年硕士论文

【摘要】：经过国内外多年的油气勘查,虽然近年来仍发现少数大型油气田,但普遍在一些油气含量较高的盆地中,勘探的重点不仅仅再是单一的大型整装油气藏,而已转变为相对多元化的,更加复杂的油气开发。在这种勘探趋势下,各个油田更加重视对岩性油气藏的研究。岩性油气藏中砂体分布随机且分散,由于中型、小型砂体是其主要的组成部分,导致储层非均质性较强,这也造成了人们对岩性圈闭的油气成藏及分布规律认识不清。论文选取渭北油田2井区长33油层为研究对象,充分利用岩心、测井等资料,同时参考了一些物理的模拟实验,对油气藏成藏与分布的特点进行分析,最终确定了不同级别的非均质性对于油气分布的影响因素。研究区长33油层组属于三角洲前缘亚相,其中水下分流河道以及河口坝微相在储层中最为发育;石英砂岩以及长石砂岩是主要的储集岩石的类型;硅质和长石质等是主要的胶结物,其次为铁方解石和水云母;储层中空隙类型以粒间溶孔和粒内溶孔为主,其中油气大多聚集在粒间溶孔。研究区压汞实验分析表明,储层排驱压力低,而对于储集岩而言,其岩性一般比较致密,属大孔-中细喉道型,中孔-细喉型空隙,而喉道半径偏大连通性较好;其中,纵向上层内以及层间的非均质性都是相对较强的,同时夹层较为发育;储层的非均质性受沉积微相控制,并受后期成岩作用影响。论文主要从三个方面来分析非均质性对油气成藏的影响。首先,从微观上来说,渭北油田2井区的主要类型是粒间空隙,主要的存储空间是大孔隙,且受非均质性的影响较大;其次,垂向上韵律性对砂体的含油量以及饱和度有很大影响,层内的交错层理有利于油气聚集,同时,流体流动会受到夹层的影响,但是一些比较厚的均质夹层对油气成藏较为有利;最后,从油气在平面上的展布特征来看,其主要受到沉积微相控制,而对油气聚集最有利的相带是水下分流河道微相以及河口坝微相。
[Abstract]:After many years of oil and gas exploration at home and abroad, although a few large oil and gas fields have been discovered in recent years, in some basins with high oil and gas content, the focus of exploration is not only on a single large integrated oil and gas reservoir. It has turned into a relatively diversified, more complex development of oil and gas. Under the trend of exploration, more attention is paid to the study of lithologic reservoirs. The distribution of sand bodies in lithologic reservoirs is random and dispersed. Because the medium and small sand bodies are the main components of the reservoirs, the heterogeneity of the reservoirs is strong, which also leads to unclear understanding of the hydrocarbon accumulation and distribution law of lithologic traps. In this paper, Chang33 reservoir in well 2 of Weibei Oilfield is selected as the research object, and the characteristics of reservoir formation and distribution are analyzed by making full use of core and logging data and referring to some physical simulation experiments. Finally, the influence factors of different levels of heterogeneity on oil and gas distribution are determined. The Chang33 formation belongs to the delta front subfacies, in which the underwater distributary channel and the estuarine dam microfacies are the most developed in the reservoir, the quartz sandstone and feldspathic sandstone are the main reservoir rocks. Siliceous and feldspar are the main cementation, followed by iron calcite and hydromica, and intergranular dissolved pores and intragranular dissolved pores are the main types of voids in the reservoir, in which oil and gas are mostly concentrated in intergranular dissolved pores. The experimental analysis of mercury injection in the study area shows that the displacement pressure of reservoir is low, but for reservoir rock, its lithology is generally compact, which belongs to the type of macropore-fine throat, mid-pore and fine-throat, and the radius of throat is better than that of Dalian. The heterogeneity in the vertical upper layer and between the layers is relatively strong and the intercalation is relatively developed while the reservoir heterogeneity is controlled by sedimentary microfacies and affected by late diagenesis. This paper analyzes the influence of heterogeneity on hydrocarbon accumulation from three aspects. First, from the microscopic point of view, the main types of well 2 in Weibei Oilfield are intergranular voids, and the main storage space is macropores, which are greatly influenced by heterogeneity. Vertical rhythm has great influence on oil content and saturation of sand body. Interlaced bedding is favorable to oil and gas accumulation, and fluid flow will be affected by intercalation, but some thick homogeneous interbeds are more favorable for hydrocarbon accumulation. Finally, according to the distribution characteristics of oil and gas on the plane, it is mainly controlled by sedimentary microfacies, and the most favorable facies zones for hydrocarbon accumulation are subaqueous distributary channel microfacies and estuarine dam microfacies.
【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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