Characteristics and influencing factors of organic-matter pores in paleogene shale, Subei Basin

Key words:  organic-matter pore  type and characteristic  external condition  maceral composition  total organic carbon  maturity  evolution rule

Abstract:

Based on the study of Paleogene shale in Subei Basin, and combining results of the Marcellus shale, this paper defined the concept of organic-matter pore, summarized its types and characteristics, discussed its influencing factors and finally concluded evolution rule of organic-matter pore. The results show that organic-matter pores generally refer to pores which are within or at the boundary of organic matter and are genetically associated with it, and they include primary and secondary organic-matter pores. Organic-matter pores display various shapes and are distributed heterogeneously. Especially when they are well developed, the internal structure is a honeycomb connecting component in the layered framework. Temperature, overburden pressure, inorganic mineral and fluid are the external conditions influencing the development of organic-matter pores and organic matter type, while maturity and content are the internal factors controlling the development of organic-matter pores. Organic-matter pores of both Paleogene shale samples in Subei Basin and the thermal simulations have the characteristics of episodic evolution, which is closely related to the fabric evolution and hydrocarbon-generating mechanism during the process of hydrocarbon generation from Kerogen.