Abstract: In order to study the influence of gravel size and strength characteristics on the propagation mode and mechanical parameters of glutenite, a heterogeneous core model of glutenite was established by using the rock fracture process simulation system RFPA. The failure process and fracture propagation law of sandy conglomerate core and the variation of elastic mechanical parameters such as compressive strength, Young's modulus and Poisson's ratio with the change of gravel size and mechanical properties were studied. The results showed that with the increase of gravel size, core model of Poisson and Young's modulus increase gradually, intensity, and increase with the decrease of the first and core crack morphology of different gravel size is almost the same; With the increase of gravel strength, the compressive strength of rock uniaxial compressive strength gradually increased, and then remained basically unchanged, mainly determined by matrix strength. The results reproduce the process of crack initiation and propagation of gravel, and the influence law of gravel size and strength on core fracture is obtained.

Key words: Conglomerate reservoir, Elastic mechanical parameters, Distribution characteristics, Gravel, Crack propagation

摘要： 为研究砾石尺寸及强度特征对砂砾岩裂纹扩展模式和力学参数的影响。采用岩石破裂过程模拟系统RFPA，建立了非均质的砂砾岩岩心模型，研究了砾石尺寸及力学性质变化对砂砾岩岩心抗压强度、杨氏模量、泊松比等弹性力学参数的变化规律。结果表明，随砾石尺寸的增加，岩心模型的泊松比与杨氏模量逐渐增加，强度先减小后增大，且不同砾石尺寸的岩心裂纹形态基本一致；随砾石强度的增大，岩石单轴抗压强度逐渐增大，而后基本保持不变，主要由基质强度决定。研究结果真实再现了砂砾岩裂纹萌生、扩展过程，得到了砾石尺寸及强度对岩心破裂的影响规律。

关键词: 砾岩油藏, 弹性力学参数, 分布特征, 砾石, 裂纹扩展