四川盆地焦石坝页岩吸附性能及页岩气的二氧化碳驱替行为研究

发布时间：2018-06-29 08:51

本文选题：页岩 + 吸附　；参考：《昆明理工大学》2017年硕士论文

【摘要】：页岩气是一种典型的新兴非常规天然气,主要由甲烷(CH4)组成。我国页岩气资源储量丰富,实现页岩气的大规模开采有利于优化能源消费结构和缓解能源对外依赖程度。目前,向深部页岩储层注入二氧化碳(CO2),既能够强化页岩气采收率,又能够减少主要人为温室气体CO2的大规模排放。鉴于上述背景,本论文选取四川盆地焦石坝地区页岩样品开展相关研究工作。具体包括:焦石坝地区页岩理化性质特征、页岩单组分CH4和CO2吸附特征及规律和饱和CH4页岩的CO2驱替行为研究。本论文主要内容和结论包括:(1)焦石坝地区页岩样品理化性质特征研究表明:①页岩样品TOC含量较低,矿物组成较复杂且主要为石英和粘土矿物,孔隙相对不发达且介/大孔孔隙发育程度较低。②页岩孔隙结构参数与TOC含量的关系取决于TOC的范围,孔隙结构参数与石英含量呈显著负相关性,而与粘土矿物含量呈正相关性。③基于N2吸/脱附表征结果的分形理论分析显示页岩孔隙结构的非均质性强于孔隙表面。孔隙分形维数与TOC含量呈U形关系趋势。孔隙分形维数与粘土矿物含量呈正相关性,而与石英含量呈负相关性。孔隙表面和孔隙结构分形维数分别与孔比表面积和孔体积呈正相关性。(2)对于页岩样品的单组分CH4和CO2吸附特征及规律研究发现:①简化的Ono-Kondo Lattice模型能够很好地描述四种页岩样品对高压CH4和CO2的吸附静力学行为。Ono-Kondo Lattice模型拟合参数表明所有页岩样品的CO2吸附能力强于CH4,且CH4和CO2在页岩上的吸附主要为物理吸附。②页岩CH4最大吸附容量与微孔参数呈良好的线性正相关性,然而页岩样品CO2最大吸附容量与微孔参数线性正相关较弱。③相同条件下,所有页岩样品的CO2对CH4的优先吸附比在2到4之间。上述结果表明注入CO2驱替页岩储层中的CH4具有可行性。(3)饱和CH4页岩样品的CO2驱替行为的研究显示:①向饱和CH4的页岩体系注入CO2能够驱替出页岩气CH4。②CH4的采收量和CO2的封存量都随着CO2注入压力的增加而增加。③本论文建立的驱替过程概念模型指出饱和CH4页岩的CO2驱替过程可以分为两个阶段,即:较低的CO2注入压力下,微孔比表面积和微孔体积较小的页岩样品具有更高的CO2的封存能力,而较高的CO2注入压力下,微孔比表面积和微孔体积较大的页岩样品具有更高的CO2的封存能力。本论文旨在考察焦石坝地区页岩理化性质特征、页岩单组分CH4和CO2吸附特征及规律和饱和CH4页岩的CO2驱替行为研究。相关研究结果和结论对于进一步探明焦石坝地区页岩储层特征和页岩气富集规律,以及实施CO2提高页岩气采收率具有较好的理论和应用价值。
[Abstract]:Shale gas is a typical emerging unconventional natural gas, mainly composed of methane (Ch 4). Shale gas reserves are abundant in China. Realizing large-scale exploitation of shale gas is conducive to optimizing the energy consumption structure and alleviating the degree of energy dependence. At present, injecting carbon dioxide (CO _ 2) into deep shale reservoirs can not only enhance shale gas recovery, but also reduce the large-scale emission of the main anthropogenic greenhouse gas CO _ 2. In view of the above background, this paper selects shale samples from Jiaoshiba area, Sichuan Basin to carry out relevant research work. It includes: physical and chemical properties of shale in Jiaoshiba area, adsorption characteristics and regularity of single-component Ch _ 4 and CO _ 2 of shale, and CO _ 2 displacement behavior of saturated Ch _ 4 shale. The main contents and conclusions of this paper are as follows: (1) the physical and chemical properties of shale samples in Jiaoshiba area show that the TOC content is low, the mineral composition is complex and the samples are mainly quartz and clay minerals. The relationship between pore structure parameters and TOC content of shale depends on the range of TOC, and there is a significant negative correlation between pore structure parameters and quartz content. The fractal analysis based on N _ 2 adsorption / desorption results shows that the heterogeneity of shale pore structure is stronger than that of pore surface. The relationship between pore fractal dimension and TOC content is U-shaped. The fractal dimension of pore is positively correlated with the content of clay minerals, but it is negatively correlated with the content of quartz. The fractal dimension of pore surface and pore structure were positively correlated with pore specific surface area and pore volume respectively. (2) the adsorption characteristics and regularity of one-component Ch _ 4 and CO _ 2 in shale samples were studied. The adsorption statics of four shale samples for high pressure Ch _ 4 and CO _ 2. The fitting parameters of Ono-Kondo Lattice model show that the adsorption capacity of CO _ 2 of all shale samples is stronger than that of Ch _ 4, and the adsorption of Ch _ 4 and CO _ 2 on shale is mainly physical adsorption of .2 shale Ch _ 4. There was a good linear positive correlation between the large adsorption capacity and the micropore parameters. However, when the linear positive correlation between the maximum adsorption capacity of CO _ 2 and the micropore parameters is weak, the preferential adsorption ratio of CO _ 2 to Ch _ 4 of all shale samples is between 2 and 4. The above results show that it is feasible to inject Ch _ 4 in shale reservoirs by CO2 flooding. (3) the study of CO _ 2 displacement behavior of saturated Ch _ 4 shale samples shows that CO _ 2 injection into the shale system of saturated Ch _ 4 can drive the recovery of shale gas Ch _ (4.2) Ch _ 4 by injection of CO _ 2 into saturated shale system. With the increase of CO2 injection pressure, the conceptual model of displacement process established in this paper indicates that the CO2 displacement process of saturated CH4 shale can be divided into two stages. Under low CO _ 2 injection pressure, the micropore specific surface area and micropore volume of shale samples have higher CO _ 2 storage capacity, while at higher CO _ 2 injection pressure, the micropore specific surface area and micropore volume of shale samples have higher CO _ 2 storage ability. Shale samples with larger micropore specific surface area and micropore volume have higher CO _ 2 storage ability. The purpose of this paper is to investigate the physical and chemical properties of shale in Jiaoshiba area, the adsorption characteristics and regularity of single-component Ch _ 4 and CO _ 2, and the CO _ 2 displacement behavior of saturated Ch _ 4 shale. The relevant research results and conclusions have good theoretical and practical value for further study of shale reservoir characteristics and shale gas enrichment law in Jiaoshiba area, as well as the application of CO2 to enhance shale gas recovery.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE377

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