Scholarlink

<p>Supercritical CO<sub>2</sub> (scCO<sub>2</sub>) fracturing offers a water-free and environmentally favorable approach in enhancing coal seam permeability while concurrently enabling carbon storage. In this study, we explore the mechanics of fracture initiation, propagation, and evolution of network morphology for scCO<sub>2</sub> injection in large cylindrical coal specimens (100 mm diameter × 200 mm height) constrained by direct and detailed observation. Triaxial fracturing tests compared the performance of supercritical (sc) CO<sub>2</sub>, liquid (L-)CO<sub>2</sub>, and gaseous CO<sub>2</sub> undergoing phase transition against water-based hydraulic fracturing. scCO<sub>2</sub> demonstrated the most minimal fracture initiation pressures and yielded complex initiation pressures that were reduced by approximately 4.6% in comparison to water. It exhibited a high degree of interconnected fracture networks in contrast to those observed in aqueous fracturing, a conclusion that was substantiated by X-ray CT imaging and acoustic emission analysis. Fully coupled thermo-hydro-mechanical-damage (THM-D) modeling reproduced key experimental fracture geometries and captured the evolution of three-dimensional damage zones, highlighting the influence of thermophysical properties and temperature–pressure coupling on fracture propagation. This methodological system of “experimental-AE/CT monitoring-THM-D modeling” demonstrate the technical potential of scCO<sub>2</sub> as an effective fracturing medium in enhancing coalbed methane recovery and promoting CO<sub>2</sub> sequestration, and establish a validated modeling framework for predicting field-scale performance.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Coupled Imaging and THM-Damage Modeling of Supercritical CO2 Fracturing in Coal

  • 期刊论文

  • 发表日期：

    2026年1月7日

查看全文
  • Liyuan Liu,
  • Yaohui Li,
  • Derek Elsworth,
  • Tao Wang,
  • Hongguang Ji,
  • Xiaodong Sun,
  • Tao Yang,
  • Kaikai Zhao,
  • Jiong Wang

摘要

Supercritical CO2 (scCO2) fracturing offers a water-free and environmentally favorable approach in enhancing coal seam permeability while concurrently enabling carbon storage. In this study, we explore the mechanics of fracture initiation, propagation, and evolution of network morphology for scCO2 injection in large cylindrical coal specimens (100 mm diameter × 200 mm height) constrained by direct and detailed observation. Triaxial fracturing tests compared the performance of supercritical (sc) CO2, liquid (L-)CO2, and gaseous CO2 undergoing phase transition against water-based hydraulic fracturing. scCO2 demonstrated the most minimal fracture initiation pressures and yielded complex initiation pressures that were reduced by approximately 4.6% in comparison to water. It exhibited a high degree of interconnected fracture networks in contrast to those observed in aqueous fracturing, a conclusion that was substantiated by X-ray CT imaging and acoustic emission analysis. Fully coupled thermo-hydro-mechanical-damage (THM-D) modeling reproduced key experimental fracture geometries and captured the evolution of three-dimensional damage zones, highlighting the influence of thermophysical properties and temperature–pressure coupling on fracture propagation. This methodological system of “experimental-AE/CT monitoring-THM-D modeling” demonstrate the technical potential of scCO2 as an effective fracturing medium in enhancing coalbed methane recovery and promoting CO2 sequestration, and establish a validated modeling framework for predicting field-scale performance.