Abstract In the last decades, the study of fluid flow through discontinuities such as fractures has received significant attention from the petroleum industry owing to the discovery of highly productive naturally fractured reservoirs. Several approaches based on an explicit or implicit representation of fractures have been adopted for modeling fluid migration in fractured rocks. The explicit approach is the most accurate for such a purpose; however, it is computationally expensive. Alternatively, the implicit representation is very attractive because fracture properties, such as stiffness and permeability can be introduced in the model through dual continuum models. Therefore, the modeling of fluid flow through fractured porous media has been performed through conceptual models, while the modelling of more realistic scenarios is still an open question. This paper proposes a new embedded fracture approach for fluid flow in highly fractured porous media. This approach includes the fracture contribution into the continuum element using a condensation technique based on the multi-constrain method. The main advantage of this approach is the guarantee of compatibility between fracture and porous matrix within a standard finite element mesh. Several fractured rock reservoir cells are analyzed to demonstrate the robustness of the proposed approach and its applicability to highly fractured rocks with random fracture orientation. The pore pressure field obtained with the proposed embedded approach is very close to the predictions provided by the explicit approach with zero-thickness interface elements. Despite the simplicity of the method, the results are promising.

中文翻译：

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一种嵌入复杂裂缝网络的三维裂缝性油藏建模新方法

摘要 在过去的几十年中，由于发现了高产天然裂缝性储层，流体通过裂缝等不连续性的研究受到了石油工业的极大关注。已经采用了几种基于裂缝显式或隐式表示的方法来模拟裂缝岩石中的流体运移。对于这种目的，显式方法是最准确的；然而，它在计算上是昂贵的。或者，隐式表示非常有吸引力，因为可以通过双连续模型在模型中引入裂缝特性，例如刚度和渗透率。因此，流体流经裂缝性多孔介质的建模是通过概念模型进行的，而更现实场景的建模仍然是一个悬而未决的问题。本文提出了一种新的嵌入裂缝方法，用于高度裂缝性多孔介质中的流体流动。这种方法包括使用基于多约束方法的凝聚技术对连续单元的断裂贡献。这种方法的主要优点是在标准有限元网格内保证裂缝和多孔基体之间的兼容性。分析了几个裂缝性岩石储层单元，以证明所提出的方法的稳健性及其对具有随机裂缝方向的高度裂缝性岩石的适用性。使用建议的嵌入方法获得的孔隙压力场非常接近于具有零厚度界面元素的显式方法提供的预测。