成果归属作者：

许浩

成果归属机构：

能源学院

作者：

Wu, Jingjie ; Xu, Hao ; Cao, Can ; Chen, Yanpeng ; Xin, Fudong ; Yin, Zhenyong

单位：

China Univ Geosci Beijing, Sch Energy Resources, Beijing 100083, Peoples R China;Minist Emergency Management, Training Acad Execut Leadership, Beijing 100012, Peoples R China;PetroChina Res Inst Petr Explorat & Dev, Beijing 100083, Peoples R China;PetroChina Shenzhen New Energy Res Inst, Shenzhen 518052, Peoples R China;Chinese Acad Geol Sci, Beijing 100037, Peoples R China

关键词：

NEGATIVE THERMAL-EXPANSION; ACOUSTIC-EMISSION; PERCOLATION THEORY; PRESSURE; CRACKING; GRANITE; STRESS; DIFFRACTION; SANDSTONE; EVOLUTION

摘要：

Syngas leakage resulting from increased permeability of the surrounding rock at high temperatures can lead to the failure of underground coal gasification projects. Current methods for predicting permeability at high temperatures often fail to capture abrupt changes at high temperatures and typically overlook the influence of petrological characteristics. To address this limitation, a prediction method for permeability at high temperatures was developed that integrates finite element method thermal stress simulations with fracture mechanic theory. This approach enables the accurate calculation of tensile stress that leads to fracturing, accounts for abrupt changes in permeability at high temperatures, and incorporates petrological characteristics. The method demonstrated strong predictive performance comparing with experimental results, with R2 exceeding 0.85 for permeability predictions in most quartz-bearing rocks, and root mean square error values remaining within acceptable limits. However, predictive accuracy declined at temperatures above 800 degrees C due to rapid cooling effects, which induced extensive fracturing in treated rock samples. Moreover, the method is not applicable to rocks undergoing significant chemical reactions at high temperatures, as such processes are not considered in the underlying assumptions. Sensitivity analysis identified quartz content, thermal stress gradient, and stress intensity factor as the primary factors influencing permeability at high temperatures. Although Young's modulus and Poisson's ratio also contribute to permeability variations, grain size was found to have a comparatively minor effect. Overall, this study advances permeability predictions at high temperatures for underground coal gasification applications and contributes numerical simulations and environmental risk assessments.

基金：

China Scholarship Council; Key Projects of China National Petroleum Corporation [2022DJ5503]; High-performance Computing Platform of China University of Geosciences Beijing

语种：

英文

DOI：

10.1016/j.fuel.2025.136195

来源：

FUEL,2026():.

出版日期：

2026-01-15

提交日期：

2025-08-21

引用参考：

Wu, Jingjie; Xu, Hao; Cao, Can; Chen, Yanpeng; Xin, Fudong; Yin, Zhenyong. A novel method for predicting permeability in quartz-bearing rocks at high temperatures during underground coal gasification[J]. FUEL,2026():.