Effect of sample crushing size on characterization of shale pore structure by small-angle X-ray scattering

doi:10.3969/j.issn.1006-6535.2026.04.005

Abstract

Abstract: At present,the influence of sample crushing size on the characterization of shale pore structure by small-angle X-ray scattering remains unclear.To solve this problem,shale samples from the Longmaxi Formation in the Sichuan Basin were selected as the research objects.The samples were crushed into four commonly used particle sizes.Small-angle X-ray scattering(SAXS)experiments were then carried out to characterize closed pores,and low-pressure nitrogen adsorption experiments were performed to characterize open pores.The experimental results show that,with decreasing sample particle size,both pore volume and fractal dimension decrease correspondingly.This indicates that sample crushing damages pores,especially larger closed pores,thereby reducing the heterogeneity and surface complexity of the sample pore system.Therefore,in order to obtain true information on shale pore structure,20-mesh samples from the Longmaxi Formation in the Sichuan Basin are recommended for small-angle X-ray scattering experiments.The results of this study will promote the standardization of small-angle X-ray scattering for shale and the comparability of the results obtained.

Key words: crushing particle size, pore structure, small-angle X-ray scattering, low-pressure nitrogen adsorption, shale

CLC Number:

TE122

Wang Jiang, Han Hui, Wen Ran, Nie Zunhao, Wu Wenjie, Wang Yixing, He Chunchen, He Jiang. Effect of sample crushing size on characterization of shale pore structure by small-angle X-ray scattering[J]. Special Oil & Gas Reservoirs, 2026, 33(4): 32-37.

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