Laboratory-scale study of hydraulic fracturing in heterogeneous media for enhanced geothermal systems and general well stimulation
AuthorFrash, Luke P.
AdvisorGutierrez, Marte S.
Keywordsenhanced geothermal systems
granular fracture mechanics
fracture fluid flow
Hydraulic fracturing -- Simulation methods
Rocks -- Permeability
Rocks -- Fracture
MetadataShow full item record
AbstractThe primary objectives of this research were to experiment with hydraulic fracturing in the laboratory to gain additional understanding of the fracturing process in unconventional rocks having low natural permeability and heterogeneous structures. Focus topics of this research included experimentation with a mechanical impulse hydraulic fracturing method, measurement of critical state hydraulic fracture aperture, laboratory scale modeling of EGS, and an investigation of grain-scale effects on 3D hydraulic fracture geometry. Fractured materials included acrylic, concrete, granite and limestone with specimen sizes up to 300x300x300 mm[superscript 3] cubical blocks. Fracturing fluids included water, brine, oil and epoxies. Applied boundary conditions varied between experiments from unconfined to true-triaxially confined with heating applied in some instances. Data collected during experiments included pressures, flow rates, acoustic emissions (AE), temperatures, strains and video with intended future application for calibration of models. Cross-sections were cut through the test specimens after hydraulic fracture stimulation to investigate and measure fracture geometry at both the grain-scale and macro-scale. Procedures for using the true-triaxial apparatus and associated control systems developed for this project are detailed in appendices to guide future use of the equipment. Supplemental data and results from the hydraulic fracture of 13 specimens are also included.
RightsCopyright of the original work is retained by the author.
Showing items related by title, author, creator and subject.
Stress-dependent fracture conductivity of propped fractures in the stimulated reservoir volume of a hydraulically fractured shale wellAbass, Hazim H.; Zhang, Di; Tutuncu, Azra; Miskimins, Jennifer L. (Colorado School of Mines. Arthur Lakes Library, 2016)The concept of stimulated reservoir volume (SRV) has been brought to the industry to stand for the shale formation areas that have been touched by hydraulic fracturing during treatment. It is a complex fracture system that allows low permeability shale plays to be productive. Recent research on shale play development has mainly focused on achieving a better understanding of the SRV system and its potential. This research aims to study SRV areas that are not well propped by conventional proppant and to quantify the contribution of these areas to the overall conductivity distribution. In addition, ultralight weight (ULW) proppant and clustered proppant fracturing are studied as they are two techniques that have potential to improve the production from SRV in shale plays. Fractures propped by conventional proppants, ULW proppants and clustered proppants were analyzed through laboratory testing. The fracture permeability architecture, the permeability from natural fracture to opened fracture and to fractures with low proppant concentration, were also studied. The different properties of ULW proppant in shale rocks were studied. A numerical model that could account for various controlling factors in clustered proppant fracturing was built. These results could act as insightful reference for field applications.
Effect of thin-bedded sands and shales on hydraulic fracture growth through the use of electrofacies and hydraulic fracture modeling, TheGraves, Ramona M.; Hurley, Neil F.; Miskimins, Jennifer L. (Colorado School of Mines. Arthur Lakes Library, 2002)