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dc.contributor.advisorNavarre-Sitchler, Alexis K.
dc.contributor.authorHayes, Amelia
dc.date.accessioned2017-06-12T20:47:04Z
dc.date.accessioned2022-02-03T13:00:21Z
dc.date.available2017-12-09T04:18:44Z
dc.date.available2022-02-03T13:00:21Z
dc.date.issued2017
dc.identifierT 8278
dc.identifier.urihttps://hdl.handle.net/11124/171003
dc.descriptionIncludes bibliographical references.
dc.description2017 Spring.
dc.description.abstractNaturally occurring fracture systems contain a separate porosity and permeability that can impact the way fluid flow through a rock by either providing flow obstruction or avenues of preferential flow. Current techniques for quantifying fracture porosity and permeability are limited to length scales of 10’s to 100’s of microns up to millimeter resolution, yet we know that pore networks in rock are fractal systems with porosity in the micron to manometer length scales. Because nano-scale pores play an important role in tight rock matrices, it is possible that pores at these length scales in natural fractures could contribute to flow either within the fracture itself or between the fracture and matrix. Here we use a combination of electron microscope techniques, cathodoluminescence imaging and small-angle neutron scattering to test the hypothesis that natural fractures that appear sealed at macroscale have connected micro- and nano-porosity. Fracture material from sub-vertical and horizontal mineralized fractures was analyzed. Estimates of micro-porosity in the analyzed vertical fractures by SEM image analysis range between 2.0 and 9.8%, but a lack of continuous grain boundary porosity suggests that the analyzed vertical fractures are not potential pathways for fluid flow. Estimated micro-porosity in horizontal fractures by SEM image analysis ranges between 0.9% and 8.3 % of fracture area and does contain connected grain boundary porosity. SANS-porosity in the horizontal fractures ranges between 0.2% – 1.7%. Preliminary FIB-SEM and TEM imaging shows that the geometry of nano-porosity is influenced by the crystal habit of the calcite fracture material. This thesis provides the first quantitative look at nano-porosity in macroscopically filled fractures and gives evidence that these pores are potentially connected and could contribute to fluid flow. Additional studies with this same approach can help build a knowledge base of nano- and micro-porosity presence in natural fractures and help elucidate their contribution to formation permeability.
dc.format.mediumborn digital
dc.format.mediummasters theses
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado School of Mines. Arthur Lakes Library
dc.relation.ispartof2017 - Mines Theses & Dissertations
dc.rightsCopyright of the original work is retained by the author.
dc.subjectelectron microscopy
dc.subjectfracture porosity
dc.subjectsmall-angle neutron scattering
dc.subjectfluid flow
dc.subjectcathodoluminescence
dc.subjectmineralized fracture
dc.titleMulti-scale characterization of porosity in naturally mineralized fractures
dc.typeText
dc.contributor.committeememberBenson, David A.
dc.contributor.committeememberGorman, Brian P.
dcterms.embargo.terms2017-12-09
dcterms.embargo.expires2017-12-09
thesis.degree.nameMaster of Science (M.S.)
thesis.degree.levelMasters
thesis.degree.disciplineGeology and Geological Engineering
thesis.degree.grantorColorado School of Mines
dc.rights.accessEmbargo Expires: 12/09/2017


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