中文摘要：

改进的Backus平均模型已被证明能较好地模拟Bakken页岩，对于同样的对象，本文采用各向异性DEM模型进行分析，分别模拟了干酪根作为岩石背景基质与内部包含物时岩石的等效弹性张量随干酪根含量的变化规律，发现将干酪根看作岩石基质时模拟结果更接近目标页岩的实验室测量数据，与目标岩样的电镜扫描结果一致；继而将粘土矿物的纵横比以及干酪根与粘土矿物的弹性模量看作自由参数，通过最小二乘法求取了各向异性DEM模型的最佳输入参数，由此得到的预测结果优于改进的Backus平均模型，说明采用各向异性DEM模型来分析有机质的含量和分布对岩石弹性性质的影响是有效可行的.最后，拟合生成了目标页岩的实际刚度系数与含氢指数的关系曲线，得出岩石刚度与干酪根成熟度之间具有正相关性.

英文摘要：

A modified version of the Backus average model was previously used to model the Bakken shale and satisfactory results have been achieved, for the same object, we propose to use the anisotropic differential effective medium （DEM） model to analyze. Through studying the variations of effective stiffness coefficients with kerogen content treating kerogen as rock background matrix and inclusions, respectively, we find that a model of discontinuous kerogen inclusions in shales gives a much better description of the measured data, which agrees with the SEM results of the target shale. Furthermore, We use the bulk and shear moduli of the isotropic end-members, as well as the aspect ratio of kerogen inclusions as free parameters, while fitting the model to the measurements using the least square method. It leads to a better match than the modified Backus average model, which indicates the validity of the anisotropic DEM model in analyzing the effect of kerogen content and kerogen distribution on the elastic properties of tight organic-rich shales. At last, by fitting the real stiffness coefficients to hydrogen index, we suggest a positive correlation between rock stiffness and kerogen maturity level.