Most of pore network models were originally designed for conventional porous media (e.g. sandstone), where pore size is at micron-scale and the dominant flow is Darcy-flow. However, those models could be inapplicable for shale (a typical unconventional porous media), since plenty of nanopores exist therein and therefore the non-Darcy effects can no longer be ignored. In this contribution, the details of shale gas flow were analyzed, and it was found that flow resistance could be misestimated by previous models. For this reason, we propose a pore network model that takes into account the influences of non-Darcy effects on pore structure. In the model, pore/throat radius and throat length are not constant but change with pressure, which is distinguishable from previous models where parameters are independent of pressure. The proposed model and previous models are defined as apparent pore network (APN) and intrinsic pore network (IPN), respectively. A shale sample, imaged by focused ion beam-scanning electron microscope, was used to extract APN and IPN, and then, their network structures were compared in the terms of throat length and throat radius. Under different pressure conditions (ranging from 0.1 MPa to 48 MPa) and image resolutions (5 nm, 10 nm, 20 nm, 50 nm, and 100 nm), shale gas flow was simulated through APN and IPN, respectively. Numerical results show that apparent permeability is likely to be erroneously predicted by IPN, while APN provides a relatively reasonable solution.

大多数孔隙网络模型最初是为常规的多孔介质（例如砂岩）设计的，其孔径为微米级，主要流动为达西流。但是，这些模型可能不适用于页岩（一种典型的非常规多孔介质），因为其中存在大量的纳米孔，因此非达西效应不再被忽略。在这一贡献中，对页岩气流动的细节进行了分析，发现以前的模型可能会误估计流动阻力。因此，我们提出了一个孔隙网络模型，该模型考虑了非达西效应对孔隙结构的影响。在模型中，孔/喉部半径和喉部长度不是恒定的，而是随压力而变化的，这与以前的模型（参数与压力无关）不同。提出的模型和以前的模型分别定义为表观孔隙网络（APN）和固有孔隙网络（IPN）。用聚焦离子束扫描电子显微镜成像的页岩样品提取APN和IPN，然后根据喉长和喉径比较它们的网络结构。在不同的压力条件下（范围从0.1 MPa到48 MPa）和图像分辨率（5 nm，10 nm，20 nm，50 nm和100 nm），分别通过APN和IPN模拟了页岩气流。数值结果表明，IPN可能错误地预测了表观渗透率，而APN提供了一个相对合理的解决方案。用APN和IPN提取网络，然后从喉长度和喉半径方面比较它们的网络结构。在不同的压力条件下（范围从0.1 MPa到48 MPa）和图像分辨率（5 nm，10 nm，20 nm，50 nm和100 nm），分别通过APN和IPN模拟了页岩气流。数值结果表明，IPN可能错误地预测了表观渗透率，而APN提供了一个相对合理的解决方案。用APN和IPN提取网络，然后从喉长度和喉半径方面比较它们的网络结构。在不同的压力条件下（范围从0.1 MPa到48 MPa）和图像分辨率（5 nm，10 nm，20 nm，50 nm和100 nm），分别通过APN和IPN模拟了页岩气流。数值结果表明，IPN可能错误地预测了表观渗透率，而APN提供了一个相对合理的解决方案。