考虑基质中流体相饱和度在压裂导流裂缝两侧的不连续性，提出一种新的嵌入裂缝模型，以准确模拟压裂后油藏中的多相流体流动状况。采用规则网格划分油藏区域，裂缝嵌入在基质网格中，通过在裂缝的两侧选择参考点，分别确定裂缝和其两侧基质之间的流量交换。在离散基质方程时，使用内边界替代含有裂缝的网格参与实际计算，有效避免了因这种网格内物理量被模糊定义而产生的误差。应用该模型分别模拟包含直裂缝和斜裂缝的油藏区域，并与离散裂缝模型及嵌入裂缝模型进行比较。结果表明：无论在基质中还是裂缝内该模型的模拟结果均与离散裂缝模型基本一致，而嵌入裂缝模型则存在一定误差；新型裂缝差分模型可以大幅度提高模拟效率。图7参24%Considering the discontinuities of flow phase saturations at the matrix-fracture interfaces, a new difference model is proposed to simulate the multi-phase flow in reservoir with conductive fractures. Structure grids are applied in the simulation to divide reservoir regions, fracture grids are embedded in matrix grids, and reference nodes are chosen at both sides of the fracture to define the exchanges between fracture and two sides of matrix. During solving the matrix equations, the discontinuities of phase saturations also lead to difficulties for defining the physical quantities on the matrix grids covering fracture, and to avoid this difficulty, inner boundary is used to replace these matrix grids in the computations. This model is used to simulate the reservoirs with straight and inclined fractures, and compared with discrete fracture model and embedded fracture model. The comparison shows that:no matter in fracture or matrix, the results from the new model are in good agreement with the discrete fracture model, but embedded fracture model has some error;the new fracture model can significantly improve the efficiency of simulation.
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