Carbonate reservoirs exhibit strong heterogeneity in the distribution of pore types that can be quantitatively characterized by applying Xu–Payne multi-porosity model. However, there are some prerequisites to this model the porosity and saturation need to be provided. In general, these application conditions are difficult to satisfy for seismic data. In order to overcome this problem, we present a two-step method to estimate the porosity and saturation and pore type of carbonate reservoirs from seismic data. In step one, the pore space of the carbonate reservoir is equivalent to a single-porosity system with an effective pore aspect ratio; then, a 3D rock-physics template (RPT) is established through the Gassmann’s equations and effective medium models; and then, the effective aspect ratio of pore, porosity and fluid saturation are simultaneously estimated from the seismic data based on 3D RPT. In step two, the pore space of the carbonate reservoir is equivalent to a triple-porosity system. Combined with the inverted porosity and saturation in the first step, the porosities of three pore types can be inverted from the seismic elastic properties. The application results indicate that our method can obtain accurate physical properties consistent with logging data and ensure the reliability of characterization of pore type.

中文翻译：

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应用Xu-Payne多孔隙模型从碳酸盐岩储层地震数据估算孔隙类型的两步法

碳酸盐岩储层在孔隙类型分布中表现出很强的非均质性，可以通过应用Xu-Payne多孔隙度模型来定量表征。但是，此模型有一些先决条件，需要提供孔隙率和饱和度。通常，这些应用条件很难满足地震数据的要求。为了克服这个问题，我们提出了一种通过地震数据估算碳酸盐岩储层孔隙度，饱和度和孔隙类型的两步法。在第一步中，碳酸盐岩储层的孔隙空间等效于具有有效孔隙纵横比的单孔隙度系统。然后，通过Gassmann方程和有效的介质模型建立3D岩石物理模板（RPT）。然后，毛孔的有效长宽比，同时根据3D RPT从地震数据中估算孔隙度和流体饱和度。在第二步中，碳酸盐储层的孔隙空间相当于三孔隙度系统。结合第一步中的倒置孔隙率和饱和度，可以从地震弹性特性中反转三种孔隙类型的孔隙率。应用结果表明，我们的方法可以获得与测井数据一致的准确物理性质，并确保了孔隙类型表征的可靠性。