The acoustic-electrical (AE) response of subsurface hydrocarbon reservoirs is highly affected by rock heterogeneity. In particular, the characterization of the microstructure of tight (low-permeability) rocks can be aided by a joint interpretation of AE data. To this purpose, we evaluate cores from a tight-oil reservoir to obtain the rock mineralogy and pore structure by X-ray diffraction and casting thin sections. Then, ultrasonic and resistivity experiments are performed under different confining pressures to analyze the effects of pores, microcracks and mineralogy on the AE properties. We have developed acoustic and electrical models based on effective-medium theories, and the Cole–Cole and triple-porosity equations, to simulate the response to total and soft (crack) porosities and clay content. The results show that these properties play a significant role. Then, a 3D rock-physical template is built and calibrated by using the core samples and well-log data. The template is applied to tight-oil reservoirs to estimate the rock properties, which are validated with log data. The good match between the predictions and these data indicates that the model can effectively explain the effects of the heterogeneous microstructure on the AE data.

地下油气藏的声电（AE）响应受岩石非均质性的影响很大。特别是，对 AE 数据的联合解释可以帮助表征致密（低渗透率）岩石的微观结构。为此，我们评估致密油储层的岩心，通过 X 射线衍射和铸造薄片获得岩石矿物学和孔隙结构。然后，在不同围压下进行超声波和电阻率实验，分析孔隙、微裂纹和矿物学对声发射特性的影响。我们已经开发了基于有效介质理论以及 Cole-Cole 和三重孔隙度方程的声学和电学模型，以模拟对总孔隙度和软（裂缝）孔隙度和粘土含量的响应。结果表明，这些特性起着重要作用。然后，利用岩心样品和测井数据构建和校准 3D 岩石物理模板。该模板应用于致密油储层以估计岩石特性，并通过测井数据进行验证。预测与这些数据之间的良好匹配表明该模型可以有效地解释异质微观结构对 AE 数据的影响。