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Original Paper | Open Access

Investigations of methane adsorption characteristics on marine-continental transitional shales and gas storage capacity models considering pore evolution

Chen-Gang Lua,bXian-Ming Xiaoa( )Zhen-Qian XuecZhang-Xin Chenc,d( )Yin-Tao DongeYue FengaGang Lia
School of Energy Resources, China University of Geosciences (Beijing), Beijing, 100083, China
School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
Chemical and Petroleum Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
Eastern Institute of Technology (tentative), Ningbo, 315000, Zhejiang, China
CNOOC Research Institute, Beijing, 100028, China

Edited by Jie Hao and Teng Zhu

Show Author Information

Abstract

Methane adsorption is a critical assessment of the gas storage capacity (GSC) of shales with geological conditions. Although the related research of marine shales has been well-illustrated, the methane adsorption of marine-continental transitional (MCT) shales is still ambiguous. In this study, a method of combining experimental data with analytical models was used to investigate the methane adsorption characteristics and GSC of MCT shales collected from the Qinshui Basin, China. The Ono-Kondo model was used to fit the adsorption data to obtain the adsorption parameters. Subsequently, the geological model of GSC based on pore evolution was constructed using a representative shale sample with a total organic carbon (TOC) content of 1.71%, and the effects of reservoir pressure coefficient and water saturation on GSC were explored. In experimental results, compared to the composition of the MCT shale, the pore structure dominates the methane adsorption, and meanwhile, the maturity mainly governs the pore structure. Besides, maturity in the middle-eastern region of the Qinshui Basin shows a strong positive correlation with burial depth. The two parameters, micropore pore volume and non-micropore surface area, induce a good fit for the adsorption capacity data of the shale. In simulation results, the depth, pressure coefficient, and water saturation of the shale all affect the GSC. It demonstrates a promising shale gas potential of the MCT shale in a deeper block, especially with low water saturation. Specifically, the economic feasibility of shale gas could be a major consideration for the shale with a depth of <800 m and/or water saturation >60% in the Yushe-Wuxiang area. This study provides a valuable reference for the reservoir evaluation and favorable block search of MCT shale gas.

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Petroleum Science
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Cite this article:
Lu C-G, Xiao X-M, Xue Z-Q, et al. Investigations of methane adsorption characteristics on marine-continental transitional shales and gas storage capacity models considering pore evolution. Petroleum Science, 2024, 21(4): 2273-2286. https://doi.org/10.1016/j.petsci.2024.03.027

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Received: 12 July 2023
Revised: 09 October 2023
Accepted: 31 March 2024
Published: 16 April 2024
© 2024 The Authors.

This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

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