基于模拟有限差分的嵌入式离散裂缝数学模型

嵌入式离散裂缝模型划分网格时不需要考虑油藏内的裂缝形态,只需对基岩系统进行简单的网格剖分,可以大大降低网格划分的复杂度,从而能够提高计算效率.并且该模型可以将现有成熟的油藏数值模拟技术和离散裂缝网络模型有机地结合起来,能精细地模拟流体在裂缝性油藏中的流动.本文模型求解采用模拟有限差分方法,该方法基于单个网格的节点和面信息构造数值计算格式,理论上适用于任何复杂网格系统,且具有良好的局部守恒性,将其推广到嵌入式离散裂缝模型后,克服了该模型基于有限差分方法求解时不能有效处理全张量形式的渗透率以及不适用于复杂边界形状裂缝性油藏的局限性.最后通过实际算例验证了本文方法的正确性和优越性.

The embeded discrete fracture model based on mimetic finite difference method

The meshing of embeded discrete fracture model （EDFM） dose not need to conside the distribution pattern of fractures. It only needs to partition grid for matrix, so it can reduce the complexity of meshing and improve the computational efficiency. The embeded discrete fracture model can combine the mature reservoir simulation technology and the discrete fracture network model It can simulate the flow of fluid in fractured reservoir accurately. We use mimetic finite difference （MFD） method to solve the model because of its local conservativeness and applicability of complex grids. The embeded discrete fracture model can deal with permeability tensor and be used to simulate fractured reservoir with complex boundary shape. Lastly, we have proven the validity and superiority of this method with some actual examples.