Shale gas has garnered significant global attention as a novel energy source. Due to its reliance on fractures within rock for production, the study of gas seepage characteristics within fractures is of paramount importance. Many scholars have conducted extensive research on the nonlinear seepage behavior of gas in fractures. However, the different geometric parameters (contact area, mechanical aperture, and roughness) of fractures are all related, and in previous studies, the geometric parameters could not be separated to study their impacts on nonlinear seepage. Two fracture surfaces were generated using three-dimensional scanning technology to obtain data of fracture surfaces. The influence of the mechanical aperture and contact area on gas nonlinear seepage can be studied by adjusting the distance between fracture surfaces to control the changes in the mechanical aperture before contact and the changes in contact area after contact. The geometric parameters that play a dominant role in gas nonlinear seepage during the process of fracture closure were obtained, and a modified cubic law correction model was proposed, which can describe the influence of fracture geometric characteristics on the nonlinear seepage behavior of gas.

中文翻译：

---

页岩裂缝几何形状对气体非线性渗流行为影响研究

页岩气作为一种新型能源受到了全球的广泛关注。由于其生产依赖于岩石内裂缝，因此裂缝内气体渗流特征的研究至关重要。许多学者对裂缝中气体的非线性渗流行为进行了广泛的研究。然而，裂缝的不同几何参数（接触面积、机械孔径和粗糙度）都是相关的，在以往的研究中，无法将几何参数分开来研究它们对非线性渗流的影响。利用三维扫描技术生成两个断口，获得断口数据。通过调节断裂面之间的距离，控制接触前机械孔径的变化和接触后接触面积的变化，可以研究机械孔径和接触面积对气体非线性渗流的影响。获得了裂缝闭合过程中对气体非线性渗流起主导作用的几何参数，提出了修正的三次定律修正模型，可以描述裂缝几何特征对气体非线性渗流行为的影响。