有机酸对东营凹陷湖相泥页岩的溶蚀作用研究

发布时间：2018-05-30 17:40

本文选题：溶蚀实验 + 有机酸　；参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：近些年来,随着页岩气勘探开发的大力发展以及现代技术手段的进步,泥页岩不仅仅能作为常规意义上的盖层,还可以作为储层来储集页岩油气。作为自生自储的系统,泥页岩中的有机酸对泥页岩储层的溶蚀作用是一个重要的自然现象,而有机酸对泥页岩储层孔隙度的影响程度以及影响有机酸溶蚀的因素是重要的科学问题,对泥页岩油气有利储层的预测有重要的意义。为研究该问题,本文借鉴了前人对于有机酸生成、水岩作用及泥页岩储集空间表征的研究成果,在综合分析录井资料、测井资料、地层数据、矿物等相关资料的基础上,通过一系列实验测试手段(有机酸溶蚀实验、有机酸生成实验、XRD、ICP、扫描电镜、氮气吸附等)对东营凹陷古近系沙三下段泥页岩样品进行了分析。有机酸对泥页岩的溶蚀实验结果显示,在溶蚀过程中造成了泥页岩矿物离子的释放、矿物组成的变化,同时还使得泥页岩样品的孔隙形态、孔径分布及比表面积发生了改变。具体来说,(1)反应温度升高,加强了泥页岩的溶蚀作用。但是不同离子的浓度随温度的变化情况不同。(2)乙酸和乙二酸对泥页岩溶蚀之后,方解石等碳酸盐矿物均基本消失殆尽,长石等铝硅酸盐矿物也呈现出了下降趋势,石英含量则基本保持稳定,除了矿物发生溶蚀外,同时也看到了新生矿物的出现,如伊利石、高岭石等粘土矿物等。(3)溶蚀之后样品的粒内孔孔径增大,分布增多,粒间孔的接触部分发生了小规模溶蚀,产生网洞化现象。除此之外,还存在着微裂缝的宽度增加现象。(4)乙酸以及乙二酸的溶蚀,均使得泥页岩的孔体积增大明显,其中乙酸对比表面积影响较大,乙二酸对平均孔径影响较大。(5)有机酸的溶蚀还使得泥页岩的孔隙结构、孔体积及比表面积组成发生了变化。有机酸生成实验结果表明有机酸生成量主要受温度、PH、TOC的控制,其中受TOC的控制最为明显,根据实验数据求取了TOC与有机酸的关系式,并据此对东营凹陷地区的有机酸生成量进行了初步模拟预测。还利用岩石物理模型及刻度测井法对泥页岩的储集空间进行了表征,然后将有机酸生成量与所得的储集空间分布图进行对比观察,发现二者具有很好的相关性,也一定程度上说明了有机酸在泥页岩储集空间上的控制作用。
[Abstract]:In recent years, with the development of shale gas exploration and development and the progress of modern technology, shale can not only be used as a conventional cap, but also as a reservoir to store shale oil and gas. The dissolution of organic acids in shale is an important natural phenomenon. The influence of organic acid on the porosity of shale reservoir and the factors affecting the dissolution of organic acid are important scientific problems, which is of great significance to predict the favorable reservoir of shale oil and gas. In order to study this problem, this paper draws lessons from the previous research achievements on organic acid formation, water-rock interaction and shale reservoir space characterization, based on the comprehensive analysis of logging data, formation data, minerals and other related data. A series of experimental methods (organic acid dissolution test, organic acid formation test, XRDX ICP, scanning electron microscope, nitrogen adsorption, etc.) were used to analyze the shale samples of the Lower Paleogene Sha3 member in Dongying Sag. The experimental results of dissolution of shale by organic acids show that the release of ions and the change of mineral composition during dissolution also change the pore morphology, pore size distribution and specific surface area of shale samples. Specifically, the increase of reaction temperature strengthens the dissolution of shale. However, the concentration of different ions varies with temperature.) after the shale is dissolved by acetic acid and adipic acid, the calcite and other carbonate minerals almost disappear, and aluminosilicate minerals such as feldspar also show a downward trend. In addition to the dissolution of minerals, the occurrence of new minerals, such as Illite, kaolinite and other clay minerals. The contact part of intergranular pores is dissolved on a small scale, resulting in mesh cavitation. In addition, there exists the phenomenon of increasing the width of microcracks. The dissolution of acetic acid and adipic acid makes the pore volume of shale increase obviously, among which acetic acid has a great effect on the specific surface area. The dissolution of organic acids also changed the pore structure, pore volume and specific surface area composition of shale. The experimental results of organic acid formation show that the amount of organic acid is mainly controlled by temperature and TOC, and the relationship between TOC and organic acid is obtained according to the experimental data. Based on this, the formation of organic acids in Dongying sag was preliminarily simulated and predicted. The reservoir space of shale is characterized by using rock physical model and calibration logging method. Then the organic acid production and the reservoir spatial distribution map are compared and observed, and it is found that there is a good correlation between them. To some extent, the control of organic acids in shale reservoir space is also explained.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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