Visualization of thermal fluid flow in rock sample by X-ray Computed Tomography

X射线计算机断层摄影术被成功地用于地质材料内流体流动的可视化。为了设计和制作高温热流体流动实验装置，在恒温条件下对岩土材料和流体进行了一系列基础实验。在此基础上，建立了一套适用于高温实验的技术链，并给出了解释实验结果的理论，即成功地将图像相减和局部区域平均技术应用于孔隙结构、含水率和流体浓度的定量分析，提出了改进的多孔介质中流体运移图像处理软件，在渗流实验方面，本文提出了一种新的方法--分步加压法，并将一维水流实验得到的系列投影相减，得到基质吸力沿着前缘的大小。此外，本文还提出了一种新的一维定流溶质定量方法，并以碘化钾溶液为示踪剂进行了成功的实例研究。结论是X-X射线层析成像技术是目前地质力学模型实验和岩石内部流体流动现象定量分析的一种很有希望的监测手段，土壤

X-ray Computed Tomohraphy was successfully utilized for the visualization of fluid flow within geo-materials. In order to design and produce the apparatus for a thermal fluid flow experiment at a high temperature, a series of fundamental experiment was performed by maintaining geo-materials and fluid at constant temperature. Consequently, a chain of technique available for a high temperature experiment was developed together with the theory for interpriting the experimental results.Namely the subtraction of serial images and the local region avaraging technique were successfully applied to the quantitative analysis of porosity structure, water ratio and concentration of fluid, and the improved sofyware was presented for image processing of the fluid migration in porous media, the strain localization in soil prior to the coefficient of permeability, the diffusion coefficient and the ispersivity required for the thermal fluid flow analysis.As concerns the fluid flow experiment, a new method called multi-step pressurization procedure has been presented together with the magnitude of the matrix suction along water front, from the subtraction of serial projections obtained by one-demensional water flow experiment. Moreover, a new one-demensional method available for the quantitative solute within porous media at constant flow rate was developed, and a successful case study was presented using the solution of potassium iodide as a tracer.From the present stydty, it is concluded that the X-ray Computed Tomography is a hopeful monitoring tool presently available for geomechanical model experiment and the quantitative analysis of fluid flow phenmena within rock and soil.