Download or read book Fluid rock Interaction Studies on an Enhanced Geothermal System in the Cooper Basin South Australia written by Gideon Bani Kuncoro and published by . This book was released on 2014 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Engineered Geothermal System (EGS) has great potential to supply electricity by harnessing stored thermal energy from high temperature granitic rocks. Since reserves of coal, oil, and natural gas are being depleted at an increasing rate, this route provides opportunities to generate electrical power without producing greenhouse gas emissions or long lasting nuclear wastes, at a cost that is competitive to those generated from fossil fuels. Australia has a vast amount of thermal area, though the heat exchange occurs at a significantly greater depth (5 km) to conventional geothermal system. Clearly, the study of fluid-rock interaction is crucial and remains largely poorly addressed and known. A compounding factor is the fact that fundamental processes associated with mineral dissolution and precipitation, and the developed pressure temperature gradient remain poorly understood. Furthermore, a number of issues relating to geothermal geochemistry are required to be considered and explored to ensure safe, economic energy production from the 'hot rocks'. Low pH and saline waters at temperatures exceeding 200°C are highly corrosive. Thus, it is vital to prevent the generation of scaling as the brines cool during transport to the surface. The objectives of this study were to investigate the geochemistry, the fluid-rock interaction, and model the precipitation rate of silica. Experimental work was carried out to observe the fluid-rock interaction, including analysis on the rock to monitor the dissolved elements in the circulating fluid, and the water chemistry after the interaction. The granite samples were analysed using x-ray diffraction and results showed that the rock consist of mainly quartz, albite and K-feldspar."--Summary page iii.

Download or read book Numerical Studies of Fluid rock Interactions in EnhancedGeothermal Systems EGS with CO2 as Working Fluid written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: There is growing interest in the novel concept of operating Enhanced Geothermal Systems (EGS) with CO2 instead of water as heat transmission fluid. Initial studies have suggested that CO2 will achieve larger rates of heat extraction, and can offer geologic storage of carbon as an ancillary benefit. Fluid-rock interactions in EGS operated with CO2 are expected to be vastly different in zones with an aqueous phase present, as compared to the central reservoir zone with anhydrous supercritical CO2. Our numerical simulations of chemically reactive transport show a combination of mineral dissolution and precipitation effects in the peripheral zone of the systems. These could impact reservoir growth and longevity, with important ramifications for sustaining energy recovery, for estimating CO2 loss rates, and for figuring tradeoffs between power generation and geologic storage of CO2.

Download or read book Simulation of Fluid rock Interactions in a Geothermal Basin Final Report QUAGMR quasi active Geothermal Reservoir written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: General balance laws and constitutive relations are developed for convective hydrothermal geothermal reservoirs. A fully interacting rock-fluid system is considered; typical rock-fluid interactions involve momentum and energy transfer and the dependence of rock porosity and permeability upon the fluid and rock stresses. The mathematical model also includes multiphase (water/steam) effects. A simple analytical model is employed to study heat transfer into/or from a fluid moving in a porous medium. Numerical results show that for fluid velocities typical of geothermal systems (Reynolds number much less than 10), the fluid and the solid may be assumed to be in local thermal equilibrium. Mathematical formalism of Anderson and Jackson is utilized to derive a continuum species transport equation for flow in porous media; this method allows one to delineate, in a rigorous manner, the convective and diffusive mechanisms in the continuum representation of species transport. An existing computer program (QUAGMR) is applied to study upwelling of hot water from depth along a fault; the numerical results can be used to explain local temperature inversions occasionally observed in bore hole measurements.

Download or read book Simulation of Fluid rock Interactions in a Geothermal Basin written by S. K. Garg and published by . This book was released on 1975 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of a Hot Dry Rock Geothermal Reservoir in the Cooper Basin South Australia written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applications of the Fluid rock Interaction Program FRIP to the Modelling of Hot Dry Rock Geothermal Energy Systems written by R. J. Pine and published by . This book was released on with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fluid rock Interaction in the Miravalles Geothermal Field Costa Rica written by Christopher Alyn Rochelle and published by . This book was released on 1990 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation of Water rock Interaction in the Yellowstone Geothermal System Using TOUGHREACT written by and published by . This book was released on 2003 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Yellowstone geothermal system provides an ideal opportunity to test the ability of reactive transport models to simulate the chemical and hydrological effects of water-rock interaction. Previous studies of the Yellowstone geothermal system have characterized water-rock interaction through analysis of rocks and fluids obtained from both surface and downhole samples. Fluid chemistry, rock mineralogy, permeability, porosity, and thermal data obtained from the Y-8 borehole in Upper Geyser Basin were used to constrain a series of reactive transport simulations of the Yellowstone geothermal system using TOUGHREACT. Three distinct stratigraphic units were encountered in the 153.4 m deep Y-8 drill core: volcaniclastic sandstone, perlitic rhyolitic lava, and nonwelded pumiceous tuff. The main alteration phases identified in the Y-8 core samples include clay minerals, zeolites, silica polymorphs, adularia, and calcite. Temperatures observed in the Y-8 borehole increase with depth from sub-boiling conditions at the surface to a maximum of 169.8 C at a depth of 104.1 m, with near-isothermal conditions persisting down to the well bottom. 1-D models of the Y-8 core hole were constructed to simulate the observed alteration mineral assemblage given the initial rock mineralogy and observed fluid chemistry and temperatures. Preliminary simulations involving the perlitic rhyolitic lava unit are consistent with the observed alteration of rhyolitic glass to form celadonite.

Download or read book Fluid rock Interaction in the Mirvalles Geothermal Field Costa Rica written by Christopher Alyn Rochelle and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation of Water rock Interaction in the Yellowstone Geothermal System Using TOUGHREACT written by P. F. Dobson and published by . This book was released on 2003 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Yellowstone geothermal system provides an ideal opportunity to test the ability of reactive transport models to accurately simulate water-rock interaction. Previous studies of the Yellowstone geothermal system have characterized water-rock interaction through analysis of rocks and fluids obtained from both surface and downhole samples. Fluid chemistry, rock mineralogy, permeability, porosity, and thermal data obtained from the Y-8 borehole in Upper Geyser Basin were used to constrain a series of reactive transport simulations of the Yellowstone geothermal system using TOUGHREACT. Three distinct stratigraphic units were encountered in the 153.4 m deep Y-8 drill core: volcaniclastic sandstone, perlitic rhyolitic lava, and nonwelded pumiceous tuff. The main alteration phases identified in the Y-8 core samples include clay minerals, zeolites, silica polymorphs, adularia, and calcite. Temperatures observed in the Y-8 borehole increase with depth from sub-boiling conditions at the surface to a maximum of 169.8 C at a depth of 104.1 m, with near-isothermal conditions persisting down to the well bottom. 1-D models of the Y-8 core hole were constructed to determine if TOUGHREACT could accurately predict the observed alteration mineral assemblage given the initial rock mineralogy and observed fluid chemistry and temperatures. Preliminary simulations involving the perlitic rhyolitic lava unit are consistent with the observed alteration of rhyolitic glass to form celadonite.

Download or read book Investigation of Water Rock Interaction in Geothermal System written by Mingxing Bai and published by . This book was released on 2014 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Study of Rock fluid Interaction Using Automated Multichannel System Operated Under Conditions of CO2 based Geothermal Systems written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Heat Transfer Investigations for Optimal Harnessing of Enhanced Geothermal Systems written by Esuru Rita Okoroafor and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Enhanced Geothermal Systems (EGS) offer the opportunity of exploiting the vast energy resources contained in hot impermeable rocks. In such rocks, the natural flow capacity of the system may not be sufficient to support adequate geothermal applications until it is enhanced by opening up existing fractures and propagating new fractures. Cold fluid is injected into the reservoir to exploit the energy resource, whose permeability has been enhanced. The increased permeability allows the fluid to circulate through the opened fractures to production or extraction well(s), thereby capturing and transporting the heat contained in the hot impermeable rock for power generation. Accurate prediction of the thermal performance of EGS depends on an understanding of how the heat transport is affected by the presence of the fracture(s) -- the primary flow conduit of EGS. These fractures may have aperture variability that could create channels and alter flow paths, affecting the availability of surface area for heat transfer. The overall goal of this study was to understand the fracture topology, investigate how it can impact flow and heat transport, and demonstrate ways Enhanced Geothermal Systems can be harnessed to optimize thermal performance. To achieve the goal of this study, a systematic fracture characterization approach was used, and numerical simulation models were used to study the physical processes that govern the interaction between the fluid and the rock during heat extraction from Enhanced Geothermal Systems. Using variogram modeling and Sequential Gaussian Simulation method, fracture apertures representing actual fractures were generated for lab-scale and field-scale investigations. Fracture characterization metrics such as the Joint Roughness Coefficient (JRC) and Hurst exponent were used in analyzing the data. Geometric anisotropy was a vital character of the generated fracture aperture distributions, which was seen to originate from the process of shearing or slip. Flow and heat transport relative to the direction of fracture shear was studied, with the perpendicular flow configuration being perpendicular to the direction of fracture shear. In contrast, the parallel flow configuration had flow in the same direction as the fracture shear direction. It was demonstrated in this study that the flow wetted surface area had a direct and significant contribution to the amount of heat extracted. For the lab-scale fractures, the JRC confirmed geometric anisotropy of the fracture aperture and was seen to have a direct correlation with the flow contact area. The lower the difference in JRC values between the perpendicular and parallel flow configurations, the more flow contact area expected in the perpendicular flow direction, which will lead to more heat extracted from the rock. From the variogram model parameters, it was deduced that high geometric anisotropy results in high differences in thermal drawdown and consequently a high difference in energy extracted. The thermal performance appeared to be better in the perpendicular flow configuration with a ratio of 70:30 for the lab-scale fractures. For the field-scale fractures, it was seen that most of the fracture aperture distributions with a geometric anisotropy ratio of 2 had Hurst exponents of fracture surface aperture variability found in nature. For all the fracture aperture distributions analyzed for the field scale, the perpendicular flow configuration resulted in better thermal performance than the parallel flow configuration with a ratio of 58:42. Furthermore, for the geometric anisotropy ratio of 2, the ratio was 70:30. The perpendicular flow configuration had the injected fluid move through tortuous flow paths. These tortuous flow paths contributed to more fracture surface area being contacted by the flowing fluid, leading to an improved thermal performance in that flow configuration. Throughout this study, temperature-dependent viscosity was used. However, a section of this study investigated the impact of using a constant viscosity in the thermohydraulic model. It was seen that for fractures with smooth, uniform apertures, for all temperature ranges and at the operating conditions being modeled, there was no significant difference between using a constant viscosity or a temperature-dependent viscosity in modeling an Enhanced Geothermal System. However, for fractures with spatial variations, it was determined that modeling with a temperature-dependent viscosity was necessary, especially for systems with high differences in reservoir and injection temperatures, and for fractures with high correlation lengths. The impact of thermal stresses on heat extraction was also investigated. An analog Enhanced Geothermal System, the Altona Field Laboratory, was also studied for thermo-mechanical influences. It was found out that the injection of hot water into the cold rock resulted in thermal stress generation and reduction in the aperture but did not cause significant changes to the temperature profile due to the small volumetric flow rate through the system. Also, anisotropic aperture distributions were studied to determine the impact of thermoelasticity on the heat extraction of Enhanced Geothermal Systems. It was shown that when thermoelasticity is taken into consideration, the thermal drawdown could either be improved or deteriorated depending on the nature of the aperture distribution. The impact of fracture aperture variability was investigated for Enhanced Geothermal Systems using supercritical CO2 as working fluids. It was established that CO2 as an EGS working fluid would result in better heat extracted from the system if the fractures are considered smooth, which agrees with related studies. However, where there is spatial variation in the fracture aperture, channeling could be detrimental to CO2, especially at high fracture correlation lengths and high mass flow rates, due to the high mobility of CO2. The following are the main contributions from this study. First, it has been demonstrated that heat transport is affected by the geometric anisotropy of fracture surfaces. It was determined that in most cases, flowing perpendicular to the direction of shear or slip results in more heat extracted due to more contact of the fluid with the rock while moving through tortuous flow paths. Secondly, the conditions under which a constant viscosity can be used in modeling EGS were determined. If the fractures are known to be smooth, have low correlation lengths, or have distributed surface areas, a constant viscosity can be used in the model, especially if the difference between the reservoir temperature and the injection water temperature is small. However, for anisotropic fracture surfaces, surfaces with high correlations lengths or high tortuosity, and when the difference between the reservoir temperature and injection water temperature is large, the use of constant viscosity could result in significant computational errors from the actual. Thirdly, it has been shown that thermal drawdown could either be improved or deteriorate when thermoelasticity is considered. This finding is different from studies previous studies that have looked into coupling thermohydromechanical processes for fractures with spatial variations and suggests that Enhanced Geothermal Systems may benefit from thermal stimulation. Finally, this work shows the first comparison between CO2 and water at a field scale considering fracture aperture variability. Recommended future work includes modeling of vertical fractures with spatial variations in fracture aperture to investigate how convection may impact the current findings; considering multiple fractures with spatial variations in the fracture aperture; considering non-Darcy flow in the simulation models; coupling geomechanics with the study of CO2 on fractures with spatial variations, and developing proxy models that are quicker to perform the thermohydraulic and thermohydromechanical simulations.

Download or read book Experimental Study on Fluid rock Interaction and Dissolution precipitation Processes at Low Temperatures with Implications for Industrial Geothermal Exploration written by Tim Gerrit Küsters and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geothermal Reservoir Engineering written by Malcolm Alister Grant and published by Academic Press. This book was released on 2011-04-01 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: As nations alike struggle to diversify and secure their power portfolios, geothermal energy, the essentially limitless heat emanating from the earth itself, is being harnessed at an unprecedented rate. For the last 25 years, engineers around the world tasked with taming this raw power have used Geothermal Reservoir Engineering as both a training manual and a professional reference. This long-awaited second edition of Geothermal Reservoir Engineering is a practical guide to the issues and tasks geothermal engineers encounter in the course of their daily jobs. The book focuses particularly on the evaluation of potential sites and provides detailed guidance on the field management of the power plants built on them. With over 100 pages of new material informed by the breakthroughs of the last 25 years, Geothermal Reservoir Engineering remains the only training tool and professional reference dedicated to advising both new and experienced geothermal reservoir engineers. - The only resource available to help geothermal professionals make smart choices in field site selection and reservoir management - Practical focus eschews theory and basics- getting right to the heart of the important issues encountered in the field - Updates include coverage of advances in EGS (enhanced geothermal systems), well stimulation, well modeling, extensive field histories and preparing data for reservoir simulation - Case studies provide cautionary tales and best practices that can only be imparted by a seasoned expert

Download or read book Petroleum Abstracts Literature and Patents written by and published by . This book was released on 1989 with total page 1528 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimentally Determined Rock fluid Interactions Applicable to a Natural Hot Dry Rock Geothermal System written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Los Alamos Scientific Laboratory is pursuing laboratory and field experiments in the development of the Hot Dry Rock concept of geothermal energy. The field program consists of experiments in a hydraulically fractured region of low permeability in which hot rock is intercepted by two wellbores. These experiments are designed to test reservoir engineering parameters such as: heat extraction rates, water loss rates, flow characteristics including impedance and buoyancy, seismic activity and fluid chemistry. Laboratory experiments have been designed to provide information on the mineral reactivity which may be encountered in the field program. Two experimental circulation systems have been built to study the rates of dissolution and alteration in dynamic flow. Solubility studies have been done in agitated systems. To date, pure minerals, samples of the granodiorite from the actual reservoir and Tijeras Canyon granite have been reacted with distilled water and various solutions of NaCl, NaOH, and Na/sub 2/CO/sub 3/. The results of these experimental systems are compared to observations made in field experiments done in a hot dry rock reservoir at a depth of approximately 3 km with initial rock temperatures of 150 to 200/sup 0/C.