The organic matter lamina

mineral composition

and pore geometry of the lamellar shale from the Shahejie Formation

Jiyang Depression

were qualitatively analyzed and the size and distribution of pores were quantitatively studied

through combined experimental methods

such as the large-area visual field splicing scanning electron microscope(SEM) technology

low temperature N

2

/CO

2

adsorption experiment

and high pressure mercury intrusion experiment.Meanwhile

the characteristics of pore distribution before and after core cleaning were compared

and the possible spaces for shale oil enrichment were analyzed.The organic matter and calcite in the samples studied are distributed in both banded and dispersed forms

and the distribution of clay minerals and quartz is complex.Although the shale samples studied are in the stage of low maturity-oil generation

organic pores are still well developed in them

which may be ascribed to the efflux or escape of some hydrocarbons(especially the light oil and gas).In addition

large number of intergranular pores

intragranular pores and micro-cracks are also developed.Low-temperature N

2

adsorption experiment(used to describe pores with diameter being less than 100 nm)and high-pressure mercury intrusion experiment(used to describe pores with diameter ranging from 100 nm to a dozen μm)and large-area visual field splicing SEM scanning can effectively reflect the full size of lacustrine shale reservoir space.Interconnected reservoir space of shale is composed of pores of nano-scale(with pore diameter being less than 300 nm)and micro-fractures(with the width of 0.5 to a dozen of μm)in micrometer scale.While shale oil mainly accumulates in pores less than about 100 nm and micro-cracks larger than about 1 μm.The analytical methods and conclusions presented in this study can be of referential value to the related studies on shale during its oil generation stage.