Evaluating Fracture Roughness and its Effect on Fluid Flow

PI建议测量一组裂缝中的水力传导性、孔径和粗糙度，这些裂缝来自不同岩石学的岩石，有或没有裂缝皮肤。将使用高分辨率X射线计算机断层扫描(HRXCT；250微米分辨率)来定义天然岩石裂缝的裂缝几何形状和表面粗糙度。在许多具有水力意义的天然裂缝中，粗糙的尺度将等于或超过孔径的尺度(即，粗糙高度超过平均孔径)。在这种情况下，表面粗糙度的经典流体力学概念根本不适用。假设如下：1.裂隙粗糙度是流体流动和溶质、胶体运移的控制因素。2.对粗糙裂缝中流体渗流的经验规律进行了改进。3.粗糙度及其影响可以从岩石学、颗粒大小和裂缝表面成分等地质因素中推断出来。该项目包括对花岗岩、砂岩、凝灰岩和碳酸盐进行水力试验、粗糙度分析和岩石学评估。

The PIs propose to measure hydraulic conductivities, apertures, and roughnesses in a suite of fractures from rocks of varying petrology with and without fracture skins. High-resolution X-ray computed tomography (HRXCT; 250micron resolution) will be used define the fracture geometry and surface roughness of natural rock fractures. In many natural fractures of hydraulic significance, the scale of the asperities will equal or exceed the scale of the aperture (i.e., the asperity heights exceed the mean aperture). In this situation, the classical fluid-mechanics concept of surface roughness simply doesn't apply. The hypotheses are: 1. Fracture roughness is a controlling factor for fluid flow and transport of solutes and colloids. 2. Improvements can be made upon the empirical laws for fluid flow in rough fractures. 3. Roughness and its effects are inferable from geological factors, including petrology, grain size, and fracture skin compositions. The project includes Hydraulic tests, roughness analysis, petrographic assessment on Granites, Sandstones, tuffs and carbonates.