The major purpose of this work was to estimate the impacts of heterogeneous conditions on the heat extraction from EGS. These impacts were estimated based on a comparison of the heterogeneous reservoir responses with the response of an equivalent isotropic homogeneous reservoir. Multiple representations of a heterogeneous reservoir were considered in this analysis. The heterogeneity is a result...

The main objective of this work is to present a new methodology for seismic reservoir characterization that provides fine-scaled reservoir models of facies and reservoir properties, such as porosity, net-to-gross, and, possibly, fluid saturation. The proposed iterative methodology is based on sequential simulations of discrete variables, namely sequential indicator simulation, and a stochastic ...

Steel-lined pressure tunnels and shafts are used to convey water from the reservoir to the turbines in high-head hydroelectric power plants. An axisymmetrical multilayer model is often considered by engineers for the design of the steel liner. Stresses and deformations can then be computed with a closed-form analytical solution in isotropic rock. When the rock is anisotropic, the lowest elastic...

Enhanced oil recovery using nitrogen injection is a commonly applied method for pressure maintenance in conventional reservoirs. Numerical simulations can be practiced for the prediction of a reservoir performance in the course of injection process; however, a detailed simulation might take up enormous computer processing time. In such cases, a simple statistical model may be a good approach to...

As a new modeling procedure of geothermal energy extraction systems, the authors present two dimensional and three dimensional modeling techniques of subsurface fracture network, based on fractal geometry. Fluid flow in fractured rock occurs primarily through a connected network of discrete fractures. The fracture network approach, therefore, seeks to model fluid flow and heat transfer through ...

Seismic reservoir characterization is a well-known technique to obtain a better understanding of hydrocarbon-bearing reservoirs by careful analysis and integration of petrophysical and seismic data. The petrophysical properties are normally obtained through the evaluation of well logs and core data. A rock physics model provides the link between these reservoir properties and the surface seismi...

The ultimate goal of geochemical studies of geothermal systems is to understand the physical-chemical processes responsible for their origin and evolution. The chemical composition of fluids (separated vapor and water), collected from fumaroles, hot springs and drilled wells at the Earth’s surface (25oC) is determined in the laboratory. Using the chemical geothermometers, conservation of mass, ...

Heat extraction mode, e.g. well layout or arrangement of wells, of enhanced or engineered geothermal system (EGS) is crucial to its performance and directly affects its commercial viability. Assuming the subsurface target hot dry rock (HDR) has been well-fractured and the created heat reservoir can be treated as a homogeneous porous medium, we numerically simulate the long-term heat extraction ...

Rock classification or assigning a type or class to a specific rock sample based on petrophysical characteristics is a fundamental technique to reduce the uncertainty in prediction of reservoir properties due to heterogeneity. One of the popular approaches is to classify a reservoir rock from the fundamentals of geology and the physics of flow at pore network scale. In this approach, rocks of s...

The concept whereby heat is recovered from a geothermal reservoir by replacing the native aqueous phase with essentially pure high-pressure carbon dioxide as the working fluid is referred to as an Enhanced Geothermal System with CO2 (EGSCO2). The concept has yet to be tested in the field, and the chemical consequences, both within the reservoir itself, and at its periphery, are not fully unders...