柴达木盆地东部石炭系页岩纳米级孔隙特征研究
发布时间：2018-09-14 19:53
【摘要】：页岩气是一种自生自储于页岩孔隙中的清洁能源,随着社会对能源需求量的增加,世界各国越来越重视对页岩气的研究和开采。中国对页岩的研究及开采要落后于发达国家,尤其对页岩微观结构观测及页岩气渗流等方面研究仍处于起步阶段。微观孔隙是页岩孔隙网络组成中数量最多的的孔隙类型,查明其结构特征及其对页岩气渗流的影响对页岩气开采至关重要。柴达木盆地是目前国内证实具有页岩气开采潜力的盆地之一,选取盆地东部石灰沟地区zk1-1井及石浅井的石炭系克鲁克组页岩展开研究。采用实验室内FESEM二次成像技术,观察页岩样品新鲜断面及氩离子抛光后的微观结构。证实研究区页岩存在基质内孔、矿物颗粒晶间孔、溶蚀孔、有机质内孔及微裂缝五种孔隙类型。利用压汞法及气体吸附法分别测定页岩宏孔、介孔及微孔的孔径分布,得出页岩平均孔径为4nm-6nm左右,孔隙度在0.86%-5.48%之间。观察孔隙分布范围从几纳米纸几微米不等,孔隙特征与美国Barnett页岩及四川盆地龙马溪组页岩相近似,可以作为页岩气储集及运移的空间通道。根据国家相关的标准,测定研究区样品的孔隙度、矿物成分、TOC、成熟度(R0)及干酪根类型等地化性质。结果表明研究区页岩矿物成分主要包括碎屑矿物、黏土矿物及碳酸盐矿物;干酪根类型主要为II型;成熟度1.32-2.05之间,属于中等水平;TOC较低,但达到最低产气要求。表明柴达木盆地石炭系为一套具有开发价值的烃源岩。为了得出孔隙特征的控制因素,分别作出其与页岩孔容的相关关系图。表明页岩孔隙受矿物成分及孔隙度影响较大,而TOC、干酪根类型及成熟度与页岩产气能力关系密切。对于页岩气的渗流主要考虑了达西流、滑脱效应及克努森扩散三种流动方式。根据达西实验的原理设计渗流实验,得出实验数据表明渗流能力与样品孔径呈正相关关系。结合质量通量模型和表观渗透率公式计算得出滑脱因子、扩散系数及达西渗透率。结果表明纳米孔中的渗流克努森扩散所占比例很小,在压力小时以滑脱为主达西流次之,随着压力升高,达西流所占比例升高,并超过滑脱效应。
[Abstract]:Shale gas is a kind of clean energy which is self-generated and stored in shale pores. With the increasing demand for energy, more and more countries in the world attach importance to the research and exploitation of shale gas. The research and exploitation of shale in China lags behind that in developed countries, especially in the observation of shale microstructure and shale gas percolation. Micropore is the most abundant pore type in the shale pore network. It is very important to find out its structural characteristics and its influence on shale gas percolation. The Qaidam Basin is one of the basins with shale gas potential confirmed in China. The zk1-1 well and the Carboniferous Kruke formation shale in the Limegou area of the eastern part of the basin and the Carboniferous Kruke formation shale are studied. The fresh section of shale samples and the microstructure after argon ion polishing were observed by FESEM secondary imaging in laboratory. It is confirmed that there are five types of pores in shale in the study area: intergranular pore, dissolved pore, organic pore and microfracture. The pore size distribution of shale macropore, mesopore and micropore was determined by mercury injection method and gas adsorption method respectively. The average pore size of shale was about 4nm-6nm, and the porosity was between 0.86% and 5.48%. The pore distribution ranges from several nanometers to several microns. The pore characteristics are similar to those of the Barnett shale in the United States and the Longmaxi formation shale in Sichuan basin, which can be used as a space channel for shale gas storage and migration. According to the relevant national standards, the porosity, mineral composition, maturity (R0) and kerogen type of the samples in the study area were determined. The results show that the mineral composition of shale in the study area is mainly composed of clastic minerals, clay minerals and carbonate minerals, the kerogen type is mainly II type, and the maturity is between 1.32 and 2.05, which belongs to the low level of II, but meets the minimum gas production requirements. It shows that Carboniferous in Qaidam Basin is a set of source rocks with development value. In order to obtain the controlling factors of pore characteristics, the correlation diagrams between porosity and shale pore volume were made. The results show that the porosity of shale is greatly affected by mineral composition and porosity, while the type and maturity of TOC, kerogen are closely related to the gas production capacity of shale. For shale gas seepage, Darcy flow, slip effect and Knudsen diffusion are considered. According to the principle of Darcy experiment, the seepage experiment is designed, and the experimental data show that the percolation ability is positively related to the pore size of the sample. The slip factor, diffusion coefficient and Darcy permeability are calculated by combining mass flux model and apparent permeability formula. The results show that the percentage of percolation and Knudsen diffusion in the nano-pore is very small. In the pressure hour, the slip flow is the second. With the increase of the pressure, the proportion of the Darcy flow increases and exceeds the slippage effect.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE31
本文编号：2243710
[Abstract]:Shale gas is a kind of clean energy which is self-generated and stored in shale pores. With the increasing demand for energy, more and more countries in the world attach importance to the research and exploitation of shale gas. The research and exploitation of shale in China lags behind that in developed countries, especially in the observation of shale microstructure and shale gas percolation. Micropore is the most abundant pore type in the shale pore network. It is very important to find out its structural characteristics and its influence on shale gas percolation. The Qaidam Basin is one of the basins with shale gas potential confirmed in China. The zk1-1 well and the Carboniferous Kruke formation shale in the Limegou area of the eastern part of the basin and the Carboniferous Kruke formation shale are studied. The fresh section of shale samples and the microstructure after argon ion polishing were observed by FESEM secondary imaging in laboratory. It is confirmed that there are five types of pores in shale in the study area: intergranular pore, dissolved pore, organic pore and microfracture. The pore size distribution of shale macropore, mesopore and micropore was determined by mercury injection method and gas adsorption method respectively. The average pore size of shale was about 4nm-6nm, and the porosity was between 0.86% and 5.48%. The pore distribution ranges from several nanometers to several microns. The pore characteristics are similar to those of the Barnett shale in the United States and the Longmaxi formation shale in Sichuan basin, which can be used as a space channel for shale gas storage and migration. According to the relevant national standards, the porosity, mineral composition, maturity (R0) and kerogen type of the samples in the study area were determined. The results show that the mineral composition of shale in the study area is mainly composed of clastic minerals, clay minerals and carbonate minerals, the kerogen type is mainly II type, and the maturity is between 1.32 and 2.05, which belongs to the low level of II, but meets the minimum gas production requirements. It shows that Carboniferous in Qaidam Basin is a set of source rocks with development value. In order to obtain the controlling factors of pore characteristics, the correlation diagrams between porosity and shale pore volume were made. The results show that the porosity of shale is greatly affected by mineral composition and porosity, while the type and maturity of TOC, kerogen are closely related to the gas production capacity of shale. For shale gas seepage, Darcy flow, slip effect and Knudsen diffusion are considered. According to the principle of Darcy experiment, the seepage experiment is designed, and the experimental data show that the percolation ability is positively related to the pore size of the sample. The slip factor, diffusion coefficient and Darcy permeability are calculated by combining mass flux model and apparent permeability formula. The results show that the percentage of percolation and Knudsen diffusion in the nano-pore is very small. In the pressure hour, the slip flow is the second. With the increase of the pressure, the proportion of the Darcy flow increases and exceeds the slippage effect.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE31
【参考文献】
相关期刊论文 前3条
1 汤良杰,金之钧,张明利,张兵山,由福报,骆静;柴达木震旦纪—三叠纪盆地演化研究[J];地质科学;1999年03期
2 刘洛夫;柴达木盆地东部地区烃源岩的生源与沉积环境[J];古地理学报;2001年02期
3 邹才能;陶士振;杨智;袁选俊;朱如凯;侯连华;贾进华;王岚;吴松涛;白斌;高晓辉;杨春;;中国非常规油气勘探与研究新进展[J];矿物岩石地球化学通报;2012年04期
相关博士学位论文 前1条
1 张西娟;柴北缘地区中新生代构造变形与构造应力场模拟[D];中国地质科学院;2007年
，本文编号：2243710
本文链接：https://www.wllwen.com/kejilunwen/shiyounenyuanlunwen/2243710.html
