Microstructural analysis of organic matter in shale by SAXS and WAXS methods  

作　　者：Kou-Qi Liu Zhi-Jun Jin Lian-Bo Zeng Meng-Di Sun Bo Liu Ho Won Jang Majid Safaei-Farouji Mohammadreza Shokouhimer Mehdi Ostadhassan 

机构地区：[1]Institute of Energy,Peking University,Beijing,100871,China [2]State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing,102249,China [3]State Key Laboratory of Continental Shale Accumulation and Efficient Development,Ministry of Education,Northeast Petroleum University,Daqing,Heilongjiang 163318,China [4]Department of Materials Science and Engineering,Research Institute of Advanced Materials,Seoul National University,Seoul,08826,Republic of Korea [5]School of Geology,College of Science,University of Tehran,Tehran,Iran [6]Department of Materials Science and Engineering,Seoul National University,Seoul,08826,Republic of Korea [7]Institute of Geosciences,Marine and Land Geomechanics and Geotectonics,Christian-Albrechts-Universit,Kiel,Germany[8]Department of Geology,Ferdowsi University of Mashhad,Mashhad,Iran

出　　处：《Petroleum Science》2022年第3期979-989,共11页石油科学（英文版）

摘　　要：Characterizing the kerogen-hosted pore structures is essential to understand the adsorption,transport and storage potential in organic-rich shale reservoirs.In this paper,we first separated the organic matter(kerogen)from the mineral matrix in four different shale samples of the Bakken Formation with different thermal maturities and then analyzed their chemical compositions using the wide-angle X-ray scattering(WAXS)method.Next,we acquired small-angle X-ray scattering(SAXS)to characterize the structure of the organic matter and see how these two will relate.The WAXS results showed that the isolated kerogens have high purity(free of inorganic minerals)and retain different chemical compositions.Moreover,SAXS analysis revealed that the isolated kerogens have similar radius of gyration(R_(g))which is around 90Åand the molecules are in the compact mode.Based on the pore size distribution analysis from the SAXS data,two main peaks were found in all of these four samples with one peak less than 40Åand the other one larger than 1000Å.Also,the TEM images revealed that Sample 1 is abundant in pores with sizes around 20 nm while Sample 2 does not have pores of that size,which agrees with the results from the pore size distribution that was obtained from the SAXS method.Ultimately,this study exhibits how different analytical instruments can provide us with useful information from complex structures of geomaterials.

关 键 词：Isolated kerogen Bakken shale SAXS WAXS Pore structures 

分 类 号：P618.13[天文地球—矿床学]