【摘要】 中国页岩油气资源丰富，但高效开采必须依赖水力压裂改造储集层。脆性是储集层改造的关键参数，也是明确工程甜点位置的核心指标。鉴于此，以东营凹陷页岩储集层为对象，综合单轴、三轴和高温高压岩石抗压实验，厘清了页岩储集层岩石力学性质及脆性特征。结合岩石能量平衡理论与脆性特征，依据岩石破裂前与破裂后的能量演化特征，构建了一种新的脆性评价方法。结果表明：单轴环境下，页岩脆性破裂显著，呈现多裂缝破裂特征，有利于储集层改造；深部高温高压环境下，温度与围压协同作用将抑制岩石脆性破裂，增强岩石延展性，页岩脆性明显降低。基于构建的脆性评价方法，明确了页岩脆性的主控因素。岩石物性参数（孔隙度、密度、声波时差）与脆性的相关性较差，矿物和弹性参数是判断脆性的有效依据，温度和压力的影响也不容忽视。研究成果有利于页岩储集层工程甜点识别，为储集层高效改造提供了理论支撑。更多还原

【Abstract】 Shale oil and gas resources are abundant in China, and hydraulic fracturing to stimulate reservoir is a significant way to efficiently develop these resources. Brittleness is a key parameter for reservoir stimulation and a core indicator for identifying engineering sweet spots. Taking the shale reservoir in the Dongying sag as an example, the rock mechanical properties and brittleness characteristics of the shale reservoir were analyzed through uniaxial, triaxial, and high-temperature, high-pressure(HTHP) compressive tests. Based on the rock energy balance theory and brittleness characteristics, as well as the energy evolution behaviors before and after rock failure, a new method for evaluating shale brittleness was proposed. The research results show that under uniaxial conditions, the shale exhibits significant brittle failure with multiple cracks, which is beneficial for reservoir stimulation. In HTHP conditions, the synergistic effect of temperature and confining pressure suppresses rock brittle fracture but strengthens rock ductility, leading to a significant reduction in brittleness. Based on the proposed brittleness evaluation method, the primary factors controlling shale brittleness were identified. It is found that the rock physical parameters(porosity, density, and acoustic travel time) is weakly correlated with brittleness, while mineral composition and elastic parameters are more effective in assessing brittleness. The effects of temperature and pressure cannot be ignored. The research results are conductive to identifying engineering sweet spots in shale reservoirs and provide a theoretical foundation for efficient reservoir stimulation.更多还原