Anna Suzuki

Abstract Understanding flow mechanisms in fractured media is essential for geoscientific research and geological development industries. This study used 3‐D printed fracture networks in order to control the properties of fracture distributions inside the sample. The accuracy and appropriateness of creating samples by the 3‐D printer was investigated by using a X‐ray CT scanner. The CT scan images suggest that the 3‐D printer is able to reproduce complex three‐dimensional spatial distributions of

Topological data analysis is an emerging concept of data analysis for characterizing shapes. A state-of-the-art tool in topological data analysis is persistent homology, which is expected to summarize quantified topological and geometric features. Although persistent homology is useful for revealing the topological and geometric information, it is difficult to interpret the parameters of persistent homology themselves and difficult to directly relate the parameters to physical properties. In thi

Numerical modeling for geothermal reservoir engineering is a crucial process to evaluate the performance of the reservoir and to develop strategies for the future development. The governing equations in the geothermal reservoir models consist of several constitutive parameters, and each parameter is given to a large number of simulation grids. Thus, the combinations of parameters we need to estimate are almost limitless. Although several inverse analysis algorithms have been developed, determini

In geothermal developments, characterizing hydrothermal flow is essential for predicting future production and designing effective development strategies. Numerical simulation models require determining a large number of input parameters to represent a reservoir. Most previous methods have estimated plausible parameters through a trial-and-error search with measurement data, which is time-consuming and dependent on the subjectivity of the analyst. In this study, we propose a machine-learning-bas

Abstract Fault zones affect the flow paths of fluids in groundwater aquifers and geological reservoirs. Fault‐related fracture damage decreases to background levels with increasing distance from the fault core according to a power law. This study investigated mass transport in such a fault‐related structure using nonlocal models. A column flow experiment is conducted to create a permeability distribution that varies with distance from a main conduit. The experimental tracer response curve is pre

Deep geological repositories for nuclear wastes consist of both engineered and natural geologic barriers to isolate the radioactive material from the human environment. Inappropriate repositories of nuclear waste would cause severe contamination to nearby aquifers. In this complex environment, mass transport of radioactive contaminants displays anomalous behaviors and often produces power-law tails in breakthrough curves due to spatial heterogeneities in fractured rocks, velocity dispersion, ads

Reinjection is crucial for sustainable geothermal developments. In order to predict thermal performances due to cold-water injection, a method was developed to estimate effective fracture surface areas (i.e., heat transfer areas). Tracer response curves at production wells are analyzed to determine flow rates and pore volumes, and the fracture surface areas are optimized by short-term thermal response curves. Because the method erases fracture apertures from the equation by combining mass and he

Reinjection is an integral part of operating enhanced geothermal systems. Since cooling of reservoirs may occur due to cold-water injection, the possible effects of injection should be assessed. Subsurface structures, especially surface areas of flow channels connecting injection and production wells, determine the onset and rate of thermal breakthrough at a production well caused by reinjection. Previously, a method to estimate the surface area using temperature data was proposed (temperature-b