四川盆地超深层泥页岩纳米孔隙特征及其地质意义

发布时间：2018-05-07 04:38

本文选题：超深层泥页岩 + 筇竹寺组　；参考：《成都理工大学学报(自然科学版)》2017年02期

【摘要】：利用SEM-PCAS孔隙定量表征技术与低压N_2等温吸附实验研究X井深度为6 875~8 042m超深层泥页岩的纳米孔隙特征,并选取四川盆地及周缘地区从地表到5km左右的样品组作为对比,探索深埋藏作用对泥页岩孔隙系统的影响。研究发现,X井志留系龙马溪组、奥陶系五峰组及下寒武统筇竹寺组超深层泥页岩32个样品的孔隙特征相似,孔隙类型以有机质孔、粒间孔为主,孔隙形态以狭长-裂缝型为主。N_2等温吸附线类型为IV-H3型,QSDFT孔径分布显示其纳米孔隙主要分布于4~16nm段,BET比表面积为8.63~16.13m2/g。与对照组样品相比,X井超深层泥页岩的孔径分布更加分散,微孔体积和微孔比表面积更小,介孔/微孔的体积比值及介孔/微孔的比表面积比值比非超深层泥页岩均具有数量级的优势。X井超深层泥页岩的孔隙特征主要受埋藏深度控制,深埋藏作用会使泥页岩孔径缩小并改变孔隙的形态。
[Abstract]:The SEM-PCAS pore quantitative characterization technique and isothermal adsorption experiment of low pressure NSP 2 were used to study the characteristics of nano-pores in the ultra-deep shale with a depth of 6 875N 8042m. The samples from the surface to the 5km in Sichuan Basin and the surrounding areas were selected as a comparison. To explore the influence of deep burial on shale pore system. It is found that 32 samples of ultradeep shale from Silurian Longmaxi formation, Ordovician Wufeng formation and Lower Cambrian Qiongzhusi formation have similar pore characteristics, and the pore types are mainly organic pore and intergranular pore. The pore morphology is mainly narrow and fissured. The isothermal adsorption line type of N2 is IV-H3 type QSDFT pore size distribution. The pore size distribution shows that the specific surface area of nano-pore is 8.63 ~ 16.13 m ~ (2 / g) in 4~16nm. Compared with the control group, the pore size distribution, the micropore volume and the specific surface area of the ultradeep shale in well X are more dispersed, and the specific surface area of the micropore is smaller than that of the control. The volume ratio of mesoporous / micropore and the specific surface area ratio of mesoporous / micropore have several advantages over non-ultra-deep shale. The pore characteristics of ultra-deep shale in X well are mainly controlled by burial depth. Deep burial will reduce the pore size of shale and change the pore shape.
【作者单位】：油气藏地质及开发工程国家重点实验室(成都理工大学);
【基金】：四川省科技计划项目(15ZC1390) 国家自然科学基金项目(41572119)
【分类号】：P618.13

【相似文献】