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

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

Minato, S. (TU Delft Applied Geophysics and Petrophysics)
Ghose, R. (TU Delft Applied Geophysics and Petrophysics)
Tsuji, Takeshi (Kyushu University)
Ikeda, Michiharu (Shikoku Research Institute)
Onishi, Kozo (Shikoku Electric Power)

2017

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.

http://resolver.tudelft.nl/uuid:efb2981c-0309-40c9-80a3-549a70ae8218

https://doi.org/10.1002/2017JB014681

2169-9313

JGR Solid Earth

Institutional Repository

journal article

© 2017 S. Minato, R. Ghose, Takeshi Tsuji, Michiharu Ikeda, Kozo Onishi