Characterization of Organic Matter-hosted Pores by SEM Method and Their Formation Mechanisms for Shales of Longmaxi Formation,Sichuan Basin
Received date: 2015-03-27
Revised date: 2015-05-22
Online published: 2015-08-10
This study illustrated that the organic matter-hosted pores vary significantly in different organic matter matrix. Three types of organic matter-hosted pores were identified in the shales of Longmaxi Formation in Sichuan Basin by combining field emission scanning electron microscopy(FE-SEM)images,X-ray diffraction and energy dispersive spectrum analysis. Pores of TypeⅠorganic matter are observed in migrated pyrobitumen. Pores of TypeⅡorganic matter are aligned parallel to the mineral edges. Pores of Type Ⅲ organic matter develop in residual kerogen. Pores of TypeⅠorganic matter are formed from the exsolution of gaseous hydrocarbons during the secondary thermal cracking of retained oil. The mechanism of typeⅡorganic matter pores remains unclear,and pores of type Ⅲ organic matter are related to the residual kerogen after hydrocarbon generation. Pores of TypeⅠorganic matter can provide more extensive connected pathways than other isolated organic matter pores as in kerogen.
Key words: Organic matter pores; SEM image; Longmaxi Formation; Sichuan Basin
YAN Jian-ping,JIA Xiang-juan,SHAO De-yong,ZHANG Yu,ZHANG Tong-wei . Characterization of Organic Matter-hosted Pores by SEM Method and Their Formation Mechanisms for Shales of Longmaxi Formation,Sichuan Basin[J]. Natural Gas Geoscience, 2015 , 26(8) : 1540 -1546 . DOI: 10.11764/j.issn.1672-1926.2015.08.1540
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