Carbonate reservoirs in the South China Sea mostly contain natural fractures with various length scales and different intensities, which causes great challenges in efficient reservoir modeling and flow simulation. Existing efforts based on dual-porosity and dual-permeability models could not reflect the characteristics of production data in certain wells. To accurately and efficiently characterize multiscale fractures, a hybrid fracture characterization method is proposed. Firstly, fractures are divided into two types according to the geometrical size and interpretation approach. Then, small-scale fractures, characterized mainly by image log interpretations, are modeled by the traditional dual-porosity/dual-permeability (DP) method. And large-scale fractures, which are characterized by seismic interpretations and dominate the flow regime, are modeled by the embedded discrete fracture method (EDFM) to achieve both accuracy and efficiency. Lastly, transmissibilities among these three types of grid mediums are calculated to generate the hybrid DP+EDFM model for flow simulation. The proposed approach is applied to a carbonate, fractured reservoir in the South China Sea. The overall procedure is fast and reliable, and water cut matches of both field and specific wells are dramatically improved. Comparing the simulation results with the conventional DP model, the proposed approach yields much more accurate predictions on rapid water breakthrough and high water cut in fractured reservoirs.

中文翻译：

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准确有效的建模方法在南海多尺度裂缝性油藏中的应用

南海碳酸盐岩储层多为不同长度尺度、不同强度的天然裂缝，对高效储层建模和流动模拟提出了巨大挑战。现有的基于双孔双渗透模型的努力无法反映某些井的生产数据特征。为了准确有效地表征多尺度裂缝，提出了一种混合裂缝表征方法。首先，根据几何尺寸和解释方法将裂缝分为两种类型。然后，主要以图像测井解释为特征的小规模裂缝通过传统的双孔隙度/双渗透率 (DP) 方法进行建模。以地震解释为特征并主导流态的大规模裂缝，由嵌入式离散断裂方法 (EDFM) 建模，以实现准确性和效率。最后，计算这三种类型的网格介质之间的传输率，以生成用于流动模拟的混合 DP+EDFM 模型。所提出的方法应用于南海的碳酸盐岩裂缝性储层。整个过程快速可靠，油田和特定井的含水匹配度得到显着提高。将模拟结果与传统 DP 模型进行比较，所提出的方法对裂缝性油藏中的快速见水和高含水率产生了更准确的预测。计算这三种类型的网格介质之间的传输率以生成用于流动模拟的混合 DP+EDFM 模型。所提出的方法应用于南海的碳酸盐岩裂缝性储层。整个过程快速可靠，油田和特定井的含水匹配度得到显着提高。将模拟结果与传统 DP 模型进行比较，所提出的方法对裂缝性油藏中的快速见水和高含水率产生了更准确的预测。计算这三种类型的网格介质之间的传输率以生成用于流动模拟的混合 DP+EDFM 模型。所提出的方法应用于南海的碳酸盐岩裂缝性储层。整个过程快速可靠，油田和特定井的含水匹配度得到显着提高。将模拟结果与传统 DP 模型进行比较，所提出的方法对裂缝性油藏中的快速见水和高含水率产生了更准确的预测。