论文标题
页岩岩石网络的压力 - 渗透性关系的数值计算
Numerical computation of stress-permeability relationships of fracture networks in a shale rock
论文作者
论文摘要
我们提出了来自Mont Terri Underground Rock实验室的Opalinus粘土中二维断裂网络的应力敏感性渗透率。这些关系可以用作分解较大空间尺度的数值模型中断裂网络渗透性的代理，并用于涉及莎莉岩石流量的各种地球仪应用中。为了获得这些关系，我们提出了一个数值程序，该程序使用实验确定的应力 - 渗透性关系来计算网络的有效渗透性。裂缝所产生的材料不连续性是通过一种简单的接触式算法来处理的，该算法解释了断裂壁之间正常相互作用，从而使我们能够在不同的压力条件下计算断裂网络的渗透性。我们将程序应用于从Mont Terri Rock实验室的两个画廊数字化的四个断裂网络。这些断裂网络是由与粘土相交的主要断层的损伤区域绘制的。当应力从1MPa到20 MPa时，网络显示出四个数量级的最大变化。我们的数值程序不仅为压力下的岩石质量建立了代表性的压力 - 渗透性关系，而且还为断裂网络渗透性提供了折断形成中的裂缝网络渗透性。
We present stress-sensitive permeability relationships for two-dimensional fracture networks in the Opalinus Clay from the Mont Terri underground rock laboratory. These relationships may be used as a proxy for fracture network permeability in numerical models that resolve large spatial scales and are used in a variety of GeoEnergy applications involving flow in shaly rocks. To obtain these relationships we present a numerical procedure that uses experimentally determined stress-permeability relationships to numerically compute the effective permeability of the network. The material discontinuities stemming from the fractures are treated by a simple contact-interaction algorithm that accounts for normal interaction between fracture walls, allowing us to calculate the permeability of a fracture network under different stress conditions. We apply the procedure to four fracture networks digitized from two galleries of the Mont Terri rock laboratory. These fracture networks are mapped from the damage zone of the Main Fault that intersects the Opalinus Clay. The networks show a maximum variation of four orders of magnitude when stress ranges from 1MPa to 20 MPa. Our numerical procedure not only establishes representative stress-permeability relationships for a fractured rock mass under stress, but also provides a proxy for fracture network permeability for simulation in fractured formations.
