东北石油大学学报2026，Vol.50Issue(1)：98-108,119,12.DOI:10.3969/j.issn.2095-4107.2026.01.007
基于ScCO2-水耦合作用的页岩微观力学特性分析
Analysis of micromechanical properties of shale under ScCO2-water coupling:a case study of outcrop shale from Longmaxi Formation in Sichuan Basin
摘要
Abstract
Supercritical carbon dioxide(ScCO2)technology has emerged as an advantageous solution for the green and efficient development of shale gas due to its significant advantages,such as effective frac-turing for production enhancement and effective protection of reservoirs.To investigate the influence of ScCO2-water coupling on the micromechanical properties of shale,outcrop samples from the Longmaxi Formation in the Sichuan Basin were subjected to drying,water-wet,and ScCO2-water coupling condi-tions.The elastic modulus and hardness were obtained through nanoindentation continuous stiffness measurement tests,and the fracture toughness was determined based on energy analysis and scanning e-lectron microscopy observations.The correlations among various micromechanical parameters were ana-lyzed.Combining X-ray diffraction and scanning electron microscopy,the influence patterns of mineral composition on mechanical properties were revealed.The results indicate that both water-wet and Sc-CO2-water coupling cause significant elastic deterioration to shale.The reductions in elastic modulus,hardness,and fracture toughness are more pronounced under ScCO2-water coupling,with decreases of 14.01％,20.99％,and 16.30％,respectively.Both theoretical derivation and experimental fitting dem-onstrate a consistent linear positive correlation among elastic modulus,hardness,and fracture tough-ness.The Longmaxi Formation shale exhibits a high proportion of brittle minerals.ScCO2-water cou-pling induces dissolution and precipitation of calcareous and siliceous minerals,leading to intensified ma-trix damage,decreased elasticity index,and increased brittleness index.These findings provide a refer-ence for characterizing the micromechanical properties of shale and designing CO2 enhanced recovery measures.关键词
页岩/纳米压痕/超临界二氧化碳/ScCO2-水耦合作用/微观力学参数/断裂韧性/龙马溪组/四川盆地Key words
shale/nanoindentation/supercritical carbon dioxide/ScCO2-water coupling effect/micro-mechanical parameters/fracture toughness/Longmaxi Formation/Sichuan Basin分类
能源科技引用本文复制引用
康瑛,宁正福,刘海峰,杨珊珊,吕方涛..基于ScCO2-水耦合作用的页岩微观力学特性分析[J].东北石油大学学报,2026,50(1):98-108,119,12.基金项目
国家自然科学基金联合基金项目(U19B6003-03-04) （U19B6003-03-04）
国家自然科学基金面上项目(51774298) （51774298）
