黔西北地区龙马溪组页岩孔隙特征

发布时间：2018-07-06 12:54

本文选题：孔隙特征 + 桐页1井　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：龙马溪组富有机质页岩是中国南方页岩气勘探的主要层位。为了研究黔西北地区龙马溪组页岩的孔隙特征,本文以桐页1井为例,对岩心样品做了N2吸附、CO2吸附、高压汞孔径分析、X—射线衍射粘土矿物及全岩分析、扫描电镜等相关实验,对桐页1井的岩石学特征、地球化学特征、孔隙特征以及孔隙发育的影响因素进行了探究。实验结果表明,桐页1井的页岩样品主要由石英、粘土矿物组成,其中石英的含量在7%~75%之间,平均含量为37%,长石含量在4%~21%之间,平均含量为9%;粘土矿物(高岭石、蒙脱石、伊利石、绿泥石)含量在7%~45%之间,平均含量为29%,主要为伊利石和蒙脱石。为了使实验结果更加准确,本次实验使用了三种不同的方法来分别检测不同孔径的孔隙。使用CO2吸附法来检测微孔(2nm),使用N2吸附法来检测中孔(2~50nm),使用高压压汞法来检测宏孔(50nm)。实验结果表明龙马溪组页岩孔隙主要发育微孔和中孔,宏孔较少;微孔与中孔的体积占了总体积的83.1%,占比表面积的95%;孔径中主孔主要位于0.8~1.6nm、3~20nm两个孔径段,微孔主要孔径主要在1.0~1.5nm之间,中孔主要孔径在4~10nm之间。在上述研究的基础上,探讨了研究区龙马溪组页岩孔隙发育主探因素。微孔、中孔和宏孔的孔隙体积与比表面积有很好的正相关性;粘土矿物含量与微孔、中孔相关性较差,与宏孔有正相关性,石英含量和微孔、中孔以及宏孔都有较好正相关性;微孔、中孔体积与页岩有机碳(TOC)呈现明显正相关性,宏孔体积与页岩有机碳(TOC)也有一定的正相关性。综合分析显示,TOC含量为该区页岩孔隙发育主要因素。
[Abstract]:The organic shale of Longmaxi formation is the main layer of shale gas exploration in southern China. In order to study the pore characteristics of shale of Longmaxi formation in northwestern Guizhou, the core samples were studied by N _ 2 adsorption of CO _ 2, high pressure mercury pore size analysis of X- ray diffraction clay minerals and whole rock analysis, taking Tongren well 1 as an example. In this paper, the petrological characteristics, geochemical characteristics, pore characteristics and the influencing factors of pore development in well Tongye 1 are studied by scanning electron microscopy and other related experiments. The results show that the shale samples of well Tongye 1 are mainly composed of quartz and clay minerals, in which the content of quartz is between 7% and 75%, the average content is 37%, the content of feldspar is between 4% and 21%, the average content is 9%, and the content of clay minerals (kaolinite, montmorillonite, etc.) The content of Illite and chlorite is between 7% and 45%, and the average content is 29%, mainly Illite and montmorillonite. In order to make the experimental results more accurate, three different methods are used to detect the pores of different pore sizes. The micropore (2nm) was detected by CO2 adsorption method, the mesopore (2~50nm) was detected by N2 adsorption method, and the macro pore (50nm) was detected by high pressure mercury injection method. The experimental results show that the shale pores of Longmaxi formation are mainly micropore and mesoporous, with less macropores, the volume of micropore and mesopore accounts for 83.1% of the total volume and 95% of the specific surface area, and the main pore size of the pore is mainly located in the two pore segments of 0.81.6 nm ~ 320nm. The main pore size of micropore is between 1.0~1.5nm and the pore size of mesopore is between 4~10nm. On the basis of the above research, the main exploration factors of shale pore development in Longmaxi formation are discussed. There is a good positive correlation between pore volume and specific surface area of micropore, mesopore and macropore, clay mineral content and micropore, mesopore and macropore, quartz content and micropore, mesopore and macropore. There was a positive correlation between mesoporous volume and shale organic carbon (TOC), and a positive correlation between macropore volume and shale organic carbon (TOC). Comprehensive analysis shows that TOC content is the main factor of shale pore development in this area.
【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】：2017
【分类号】：P618.13

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