Investigation on inversion methods for tracing the sources of shale nanopores via low-temperature ashing

doi:10.3969/j.issn.1006-6535.2025.04.003

Abstract

Abstract: To address the limitations of traditional methods in studying shale nanopore sources,low-temperature ashing experiments were conducted.This study analyzed pore changes and transformation during ashing,established an inversion method for tracing organic and inorganic sources of shale micropores and mesopores,and applied such method to analyze the organic and inorganic sources of nanopores in marine-continental transitional shales at the eastern margin of the Ordos Basin.The study results show that organic matter contributes on average 45.77% to micropore volume and 44.62% to specific surface area,and 7.77% to mesopore volume and 12.85% to specific surface area.Organic micropores and mesopores are approximately 18.0 and 1.7 times larger than inorganic ones.Compared with the traditional correlation analysis method,the low-temperature ashing inversion method overcomes the influence of pore heterogeneity in organic matter on the analysis results,and is able to effectively quantify the true pore source of organic matter in each sample;the source of the shale′s micropores and mesopores is mainly controlled by the content of organic matter,with a more pronounced effect on micropores.This method enhances our understanding of shale gas storage mechanisms,free methane content,and release efficiency.

Key words: low-temperature ashing experiment, pore source, inversion method, linear regression, pore transformation

CLC Number:

TE155

SONG Dangyu, YANG Chunlin, LI Yunbo, QIAO Yu. Investigation on inversion methods for tracing the sources of shale nanopores via low-temperature ashing[J]. Special Oil & Gas Reservoirs, 2025, 32(4): 25-32.

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