دورية أكاديمية
Tectonic Control on Shale Pore Structure and Gas Content from the Longmaxi Formation Shale in Southern Sichuan Basin, China: Insights from Fractal Analysis and Low-Pressure Gas Adsorption
| العنوان: | Tectonic Control on Shale Pore Structure and Gas Content from the Longmaxi Formation Shale in Southern Sichuan Basin, China: Insights from Fractal Analysis and Low-Pressure Gas Adsorption |
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| المؤلفون: | Xuewen Shi, Zhikai Liang, Yuran Yang, Yi Li, Zhenxue Jiang, Yanyou Li, Runtong Li, Feiyong Deng |
| المصدر: | Processes, Vol 11, Iss 2873, p 2873 (2023) |
| بيانات النشر: | MDPI AG |
| سنة النشر: | 2023 |
| المجموعة: | Directory of Open Access Journals: DOAJ Articles |
| مصطلحات موضوعية: | complex tectonic area, pore structure, heterogeneity, fractal theory, low-pressure gas adsorption, Longmaxi Formation, Chemical technology, TP1-1185, Chemistry, QD1-999 |
| الوصف: | Tectonic deformation of different intensities significantly controls shale pore structure, seepage channels, and gas content. The Longmaxi Formation shales in the southern Sichuan Basin have experienced multi-stage tectonic movements, resulting in a diverse fracture system and tectonic deformation. This study focuses on three representative tectonic morphologies: deeply buried strongly deformed (DBSD), deeply buried weakly deformed (DBWD) and shallowly buried weakly deformed (LBWD). We investigated the pore structure characteristics and heterogeneity of these shales under various tectonic conditions using total organic carbon (TOC) content, X-ray diffraction (XRD), scanning electron microscopy (SEM), a low-pressure N 2 /CO 2 adsorption experiment (LP-N 2 /CO 2 GA), and multi-scale fractal theory. The results reveal that strong tectonic compression and deformation conditions lead to the compression and flattening of organic pores by brittle minerals, resulting in long, oriented OM pores. Fracturing of brittle pore creates multiple internal fracture systems linked to dissolution pores, forming a complex micro-fracture–pore network. With intense tectonic deformation, mesopores tend to be compressed, increasing micropore pore volume (PV) and surface area (SA). The DBSD shale exhibits the highest micropore heterogeneity, while the LBWD shale shows the lowest heterogeneity. Fractal analysis indicates a significant decrease in micropore fractal dimension ( D f ) with increasing burial depth. In contrast, the surface and matrix fractal dimensions ( D s and D m ) of low-buried shale micropores and meso-macropores align vertically. Shale reservoirs in tectonically stable regions exhibit more favourable gas-bearing characteristics than strongly tectonically deformed areas. The LBWD has stable tectonic conditions that are favourable for shale gas preservation. Conversely, slip faults under deep burial conditions lead to extrusion and deformation of shale pore space, ultimately compromising the original reservoir capacity ... |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| تدمد: | 2227-9717 |
| العلاقة: | https://www.mdpi.com/2227-9717/11/10/2873Test; https://doaj.org/toc/2227-9717Test; https://doaj.org/article/73e90eccef5e49bdb95b66d9647971f3Test |
| DOI: | 10.3390/pr11102873 |
| الإتاحة: | https://doi.org/10.3390/pr11102873Test https://doaj.org/article/73e90eccef5e49bdb95b66d9647971f3Test |
| رقم الانضمام: | edsbas.416BB227 |
| قاعدة البيانات: | BASE |
| تدمد: | 22279717 |
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| DOI: | 10.3390/pr11102873 |