页岩气储层气体赋存和解吸规律及影响因素研究

发布时间：2018-04-20 15:02

本文选题：等量吸附热 + 极限吸附热　；参考：《西安石油大学》2017年硕士论文

【摘要】：本文以鄂尔多斯盆地南部长7储层页岩为研究对象,运用X射线衍射技术、地球化学实验定量分析了研究区页岩的矿物组分、有机质丰度、干酪根组分和有机质成熟度;运用氩离子抛光—电镜扫描和CT扫描技术分析了页岩样品内部储集空间类型;运用压汞、核磁共振、低温氮气吸附等实验定量表征了页岩中孔隙的孔径分布特征及比表面积;基于甲烷的等温吸附实验和Knudsen数分析了页岩气在储层中的赋存特征,并通过计算甲烷的等量吸附热和极限吸附热结合多元线性回归方法研究了页岩组分对甲烷的吸附作用,分析了影响甲烷吸附解吸的因素。研究结果表明:储层温度、压力条件下页岩气的主要赋存形式为吸附态,其次为游离态;页岩中对甲烷有吸附作用的组分为伊/蒙混层和有机质,并且有机质对甲烷的吸附能力强于伊/蒙混层;吸附气主要赋存于孔径为1~3nm的孔隙表面,游离气主要赋存于中孔、宏孔和裂缝中;温度和压力恒定时吸附气含量与页岩比表面积、有机质丰度和伊/蒙混层相对含量呈正相关;温度恒定时,在一定压力范围内,甲烷吸附量随着压力升高而增大,甲烷解吸量随着压力降低而增大;压力恒定时,在一定温度范围内,甲烷解吸量随着温度升高而增大,甲烷吸附量随着温度降低而增大。影响页岩中气体赋存规律的外部因素为温度和压力,内部因素为页岩中有机质丰度、伊/蒙混层相对含量和比表面积。
[Abstract]:In this paper, taking the shale of Nanchang7 reservoir in Ordos Basin as the research object, the mineral composition, organic matter abundance, kerogen component and maturity of the shale in the study area are quantitatively analyzed by using X-ray diffraction technique and geochemical experiments. The internal reservoir space types of shale samples were analyzed by argon ion polishing, electron microscope scanning and CT scanning, and pore size distribution and specific surface area of shale pores were quantitatively characterized by mercury injection, nuclear magnetic resonance and nitrogen adsorption at low temperature. Based on the isothermal adsorption experiment of methane and Knudsen number, the occurrence characteristics of shale gas in reservoir are analyzed, and the adsorption of shale components on methane is studied by calculating the isothermal adsorption heat and limit adsorption heat of methane combined with multivariate linear regression method. The factors affecting the adsorption and desorption of methane were analyzed. The results show that the main forms of shale gas under reservoir temperature and pressure are adsorption state, followed by free state, and the components of methane adsorption in shale are Iraq / Mongolia layer and organic matter. The adsorption ability of organic matter to methane is stronger than that of eosin / monolayer, the adsorption gas mainly occurs on the pore surface with pore size of 1~3nm, and the free gas mainly occurs in mesopore, macropore and fracture. The adsorption gas content was positively correlated with the specific surface area of shale, the abundance of organic matter and the relative content of eosinite at constant temperature and pressure, and the adsorption capacity of methane increased with the increase of pressure when the temperature was constant. When the pressure is constant, the amount of methane desorption increases with the increase of temperature, and the amount of methane adsorption increases with the decrease of temperature. The external factors affecting the gas occurrence in shale are temperature and pressure, while the internal factors are the abundance of organic matter in shale, the relative content of Iraq / monolayer and the specific surface area.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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