Hydraulic properties of closely-spaced dipping open fractures intersecting a fluid-filled borehole derived from tube-wave generation and scattering: Dipping fractures from tube waves
| Autor: | Takeshi Tsuji, Shohei Minato, Michiharu Ikeda, Kozo Onishi, Ranajit Ghose |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Cataclasite
010504 meteorology & atmospheric sciences Scattering Borehole 010502 geochemistry & geophysics 01 natural sciences Tectonics Geophysics Space and Planetary Science Geochemistry and Petrology Earth and Planetary Sciences (miscellaneous) Fracture (geology) Volume of fluid method Tube (fluid conveyance) Geothermal gradient Geology Seismology 0105 earth and related environmental sciences |
| Zdroj: | JGR Solid Earth |
| ISSN: | 2169-9313 |
| Popis: | Fluid-filled fractures and fissures often determine the pathways and volume of fluid movement. They are critically important in crustal seismology and in the exploration of geothermal and hydrocarbon reservoirs. We introduce a model for tube-wave scattering and generation at dipping, parallel-wall fractures intersecting a fluid-filled borehole. A new equation reveals the interaction of tube wavefield with multiple, closely-spaced fractures, showing that the fracture dip significantly affects the tube waves. Numerical modeling demonstrates the possibility of imaging these fractures using a focusing analysis. The focused traces correspond well with the known fracture density, aperture and dip angles. Testing the method on a VSP dataset obtained at a fault-damaged zone in the Median Tectonic Line, Japan presents evidences of tube waves being generated and scattered at open fractures and thin cataclasite layers. This finding leads to a new possibility for imaging, characterizing and monitoring in-situ hydraulic properties of dipping fractures using the tube wavefield. |
| Databáze: | OpenAIRE |
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