Author: Paul KrugerPublisher:
ISBN:
Category :
Languages : en
Pages : 50
Book Description
Experimental Studies on Heat Extraction from Fractured Geothermal Reservoirs
Author: Paul KrugerAn Experimental Study of Creation of Optimal Fracture Network for Heat Extraction from Engineered Geothermal Reservoirs
Author: Banambar SinghPublisher:
ISBN:
Category :
Languages : en
Pages : 290
Book Description
Enhanced geothermal system has been successfully able to increase the permeability of the reservoir and hydro-fracturing is the conventional method of creating artificial fracture system. But more precise technique is required to reduce the cost of the geothermal energy extraction and this will require proper understanding of the thermo-mechanical behaviour of the reservoir rocks i.e. Granites. Current research work has focused on the thermo-mechanical properties of granites under various temperature and strain rate condition. Granites of two different areas i.e. Bundelkhand granite, India and Harcourt granite, Australia have been investigated for the research work. 4 different strain rates i.e. 0.05 mm/min, 0.5 mm/min, 5.0 mm/min and 50 mm/min at 3 different temperatures i.e. room temperature (25 °C), 200 °C and 400 °C were considered for experimental analysis. It was observed that at room temperature, with increasing strain rate the uniaxial compressive strength of the rock increases and the same trend is also observed at higher temperatures conditions. Whereas at low strain rate the compressive strength decreases with increase in temperature, while the trend is irregular at higher strain rates. Bundelkhand granites have thermal conductivity values between 3.1 to 3.6 W/m.K whereas that of Harcourt granite is 2.4 W/m.K. Sieve analysis of the fragmented particles due to UCS test suggested that there is no effect of strain rate on particle size distribution whereas higher temperatures produces more finer particles. It was observed that more than 75% of the fragmented particles are having diameter of greater than 11.3 mm. Effective size i.e. D10 was analysed and found that at room temperature (25 °C) 10% of fragmented particles are finer than 3.0 mm whereas at 200 °C and 400 °C 10% of finer particles are finer than 1.9 mm and 1.5 mm respectively. Numerical simulation results of the numerical simulation are quite analogous to the lab experimental data.
Comparison of Two Hot Dry Rock Geothermal Reservoirs
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Two hot dry rock (HDR) geothermal energy reservoirs were created by hydraulic fracturing of granite at 2.7 t o 3.0 km (5000 to 10000 ft) at the Fenton Hill site, near the Valles Caldera in northern New Mexico. Both reservoirs are research reservoirs, in the sense that both are fairly small, generally yielding 5 MWt or less, and are intended to serve as the basic building blocks of commercial-sized reservoirs, consisting of 10 t o 15 similar fractures that would yield approximately 35 MWt over a 10 to 20 yr period. Both research reservoirs were created in the same well-pair, with energy extraction well number 1 (EE-1) serving as the injection well, and geothermal test well number 2 (GT-2) serving as the extraction, or production, well. Evaluation of the second reservoir was accomplished in two steps: (1) with a 23-day heat extraction experiment that began October 23, 1979, the results of which are described by Murphy (1980), and (2) a-second, longer-term heat extraction experiment still in progress, which as of November 25, 1980 has been in effect for 260 days. The results of this current experiment are compared with earlier experiments.
Hydraulic fracturing and geothermal energy
Author: S. Nemat-NassarPublisher: Springer Science & Business Media
ISBN: 9400968841
Category : Science
Languages : en
Pages : 519
Book Description
Hydraulic fracturing has been and continues to be a major techno logical tool in oil and gas recovery, nuclear and other waste disposal, mining and particularly in-situ coal gasification, and, more recently, in geothermal heat recovery, particularly extracting heat from hot dry rock masses. The understanding of the fracture process under the ac tion of pressurized fluid at various temperatures is of fundamental scientific importance, which requires an adequate description of thermomechanical properties of subsurface rock, fluid-solid interaction effects, as well as degradation of the host rock due to temperature gradients introduced by heat extraction. Considerable progress has been made over the past several years in laboratory experiments, analytical and numerical modeling, and in-situ field studies in various aspects of hydraulic fracturing and geothermal energy extraction, by researchers in the United States and Japan and also elsewhere. However, the results have been scattered throughout the literature. Therefore, the time seemed ripe for bringing together selected researchers from the two countries, as well as observers from other countries, in order to survey the state of the art, exchange scientific information, and establish closer collaboration for further, better coordinated scientific effort in this important area of research and exploration.
Analysis of Heat Transfer and Energy Recovery in Fractured Geothermal Reservoirs
Author: Energy Extraction Experiments in the SGP Reservoir Model
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Experiments are being conducted in the Stanford Geothermal Program (SGP) large geothermal reservoir model utilizing rock systems with several characteristics resembling high permeability, fracture-stimulated systems. The broad objective of these experiments is to evaluate nonisothermal fluid production and heat transfer processes and to analytically model these for such rock systems. Three nonisothermal energy extraction and production processes, referred to here as in-place boiling, sweep, and steam-drive, were considered during the early phases of this study. The results showed that all three processes are feasible in the experimental systems considered. However, the effectiveness of the processes varied widely. The simple analytic models developed for the model reservoir and for the heat transfer from the rock successfully predicted the experimental results as long as the assumptions inherent in the models were not seriously violated. However, it was recognized that more detailed experimental and analytic studies of the heat transfer aspects were required, and such studies have since been performed by Iregui [Reference 4]. The final report of these results is in preparation and the highlights are given below. 2 tabs., 5 refs., 4 figs.
Energy Research Abstracts
Author: Autograph Letters Signed from Sydney Grundy to Augustin Daly
Author: Thermal Stress Cracking and the Enhancement of Heat Extraction from Fractured Geothermal Reservoirs
Author: Hugh D. MurphyPublisher:
ISBN:
Category : Fracture mechanics
Languages : en
Pages : 17
Book Description
Geothermal Reservoir Engineering
Author: Malcolm Alister GrantPublisher: Academic Press
ISBN: 0123838819
Category : Technology & Engineering
Languages : en
Pages : 379
Book Description
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