渝东北城口北相区寒武系页岩储集层特征研究

Features of Shale Reservoir of Cambrian System in Chengkou North Face of Northeastern Chongqing

以渝东北城口地区预探井A井寒武系鲁家坪组-巴山组泥页岩样品测试分析数据为基础,从页岩的地球化学特征、岩石矿物学特征、储层物性特征、储集空间特征和含气性特征等方面对泥页岩进行了初步研究。结果表明,城口地区寒武系鲁家坪组-巴山组泥页岩有机质含量高,TOC平均为5.6%;成熟度高,Ro平均为3.17%;有机质类型主要为Ⅰ型干酪根,页岩脆性矿物含量高。泥页岩储集空间类型多样,以矿物粒间孔隙为主。高压压汞、核磁共振、等温吸附数据都表明该套泥页岩大孔较发育,单位吸附量大。总含气量不高。通过对比北美Barnett页岩、焦石坝页岩和彭水区块页岩的特征,可以看出渝东北城口北相区寒武系鲁家坪组-巴山组的页岩气含气性较低,有机质孔隙较少,有机质成熟度过高等不利因素可能会加大后期开发的难度。

Based on the experiments on the shale core of well A in the Lujiaping and bashan formation in Chengkou of northeastern Chongqing,the organic geochemical signatures, petrography, mineralogy, physical properties,reservoir spaces and gas-bearing properties are treated. These shales have a higher total organic carbon（ TOC） with an average of 5. 6%,higher maturity levels of organic matter with an average Ro values of 3. 17%,the shales are characterized by type Ⅰorganic matter,and the brittle mineral content is high. These shales have different types of reservoir spaces,most of the spaces are intergranular pores. Mercury penetration,NMR and isothermal adsorption show that there are large number of micro pores in these shales,and have large adsorptive capacity but low gas content. Compared with Barnett shale gas in north America,shale gas in Jiaoshiba area and shale gas in Penyshui area,the low gas content,less of organic pores and very high maturity may have adverse effects on the exploration of the well.