高演化富有机质页岩储层特征及孔隙形成演化——以黔南地区下寒武统九门冲组为例

发布时间：2018-11-13 08:18

【摘要】：为厘清高演化富有机质页岩孔隙特征及形成机理,以上扬子黔南地区下寒武统九门冲组页岩为例,采用岩石薄片、全岩X射线衍射、低温氮气吸附、高压压汞-吸附联合测定、氦气孔隙度测试、氩离子抛光-扫描电镜、热演化史及孔隙演化史恢复等多种技术方法,开展了高演化富有机质页岩孔隙结构、类型及储集性能研究,并基于成岩压实和热演化过程建立了富有机质页岩微观孔隙形成演化模式。研究结果表明:(1)下寒武统高演化富有机质页岩总比表面积平均值为12.66 m2/g,总孔容平均值为11.54×10-3cm3/g,两者具有较好的正相关关系,与下志留统页岩相比,总比表面积与总孔容均略低。孔隙以微孔和介孔为主,宏孔基本不发育。(2)富有机质页岩孔隙类型以有机质孔为主,孔径极小,一般以小于30nm为主,孔边界形态不规则,无机质矿物质孔基本不发育。(3)与志留系页岩相比,其储集性能相对较差,平均孔隙度仅为2.80%,水平渗透率为垂直渗透率的1~3倍,平均值约2倍,反映其水平页理欠发育。(4)高演化富有机质页岩孔隙形成演化主要受成岩压实作用控制的无机质矿物粒间孔隙演化过程、热演化作用控制的生烃—成油—油气转化序列中有机质孔隙的形成过程及后期孔隙保存状态下天然气散失与补给平衡过程共同控制。
[Abstract]:In order to clarify the pore characteristics and formation mechanism of highly evolved organic-rich shale, the shale of the Lower Cambrian Jiumenchong formation in the Yangzi Qiannan area was determined by rock thin slice, X-ray diffraction of whole rock, nitrogen adsorption at low temperature and mercury pressure adsorption under high pressure. Studies on pore structure, types and reservoir properties of highly evolved organic matter rich shale have been carried out by means of helium porosity test, argon ion polishing scanning electron microscope, thermal evolution history and pore evolution history recovery, and other technical methods, such as helium gas porosity test, argon ion polishing and scanning electron microscope, thermal evolution history and pore evolution history recovery, etc. Based on the process of diagenetic compaction and thermal evolution, the evolution model of micropore formation of organic shale is established. The results show that: (1) the average total specific surface area of the organic rich shale in the Lower Cambrian evolution is 12.66 m2 / g, and the average pore volume is 11.54 脳 10 ~ (-3) cm ~ (-3) / g, which has a good positive correlation with that of the Lower Silurian shale. The total specific surface area and total pore volume are slightly lower. The pores are mainly micropore and mesoporous, and the macro pore is not developed. (2) the pore type of organic shale is mainly organic pore, pore size is very small, the pore size is smaller than 30nm, and the pore boundary is irregular. (3) compared with Silurian shale, its reservoir performance is relatively poor, the average porosity is only 2.80, the horizontal permeability is 1 ~ 3 times of vertical permeability, the average is about 2 times. (4) the pore formation and evolution of highly evolved organic matter rich shale is mainly controlled by diagenetic compaction. The formation process of organic matter pores in the hydrocarbon generating oil-forming hydrocarbon transformation sequence controlled by thermal evolution and the process of natural gas loss and recharge equilibrium in the late pore preservation state are jointly controlled.
【作者单位】：页岩油气富集机理与有效开发国家重点实验室;中国石油化工集团公司页岩油气勘探开发重点实验室;中国石油化工股份有限公司石油勘探开发研究院;北京大学地球与空间科学学院;
【基金】：国家重大科技专项(2016ZX05060、2016ZX05061) 中国石油化工股份有限公司科技部项目(P15114)资助
【分类号】：P618.13

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