Coreflooding experiments are one of the primary methods for reservoir rock characterization and have been developing in recent years, providing increasing detail. An advanced analysis of coreflooding experiments consists of constructing three dimensional permeability (k) maps of the core sample with sub-core resolution. Such detailed characterizations provide important information on the core heterogeneity and enable the construction of accurate numerical flow models that can reproduce experimental results. This work presents a method for estimating k, combining data from multiple coreflooding experiments, and studies the estimation accuracy considering a large number of test cases consisting of synthetic data obtained by numerical experiments. Cases include varying parameters, such as: fluid injection flow rates and types, relative permeability curves, capillary pressure functions and core heterogeneity. The new method is shown to significantly improve the estimation accuracy in comparison to methods that incorporate data only from a single experiment. Furthermore, a method for improving k estimations in regions where water is trapped is presented and its implementation is shown to increase the overall accuracy of k estimation. An additional method is considered, that requires only single-phase flow solutions, thus increasing the computational efficiency. However, it is shown to be applicable only for a small subset of cases.

中文翻译：

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岩心驱实验的亚岩心渗透率估计：用于评价精度和改进方法的数值分析


岩心驱实验是储层岩石表征的主要方法之一，近年来不断发展，提供了越来越多的细节。岩心驱油实验的高级分析包括构建具有亚岩心分辨率的岩心样品的三维渗透率 （k） 图。如此详细的表征提供了有关堆芯非均质性的重要信息，并能够构建可以再现实验结果的精确数值流动模型。这项工作提出了一种估计 k 的方法，结合了来自多个岩心驱实验的数据，并研究了考虑由数值实验获得的合成数据组成的大量测试用例的估计准确性。情况包括不同的参数，例如：流体注入流速和类型、相对渗透率曲线、毛细管压力函数和核心异质性。与仅包含来自单个实验的数据的方法相比，新方法被证明可以显著提高估计准确性。此外，提出了一种在水被困区域改进 k 估计的方法，并表明其实施可以提高 k 估计的整体准确性。考虑了另一种方法，该方法只需要单相流解，从而提高了计算效率。但是，它被证明仅适用于一小部分情况。