Fracture characterization from attenuation of Stoneley waves across a fracture
Author(s)
Bakku, Sudhish Kumar; Fehler, Michael; Burns, Daniel R.
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Other Contributors
Massachusetts Institute of Technology. Earth Resources Laboratory
Metadata
Show full item recordAbstract
Fractures contribute significantly to the permeability of a formation. It is important to understand the fracture distribution and fluid transmissivity. Though traditional well logs can image fractures intersecting the borehole, they provide little information on the lateral extent of the fractures, away from the borehole, or the fluid transmissivity. Experiments in the past demonstrated that fracture compliance can be a good proxy to fracture fluid conductivity. We describe a method to estimate fracture compliance from the attenuation of Stoneley waves across a fracture. Solving the dispersion relation in the fracture, transmission coefficient of Stoneley waves across a fracture is studied over all frequency ranges. Based on the observations from the model, we propose that measuring the transmission coefficient near a transition frequency can help constrain fracture compliance and aperture. Comparing attenuation across a finite fracture to that of an infinitely long fracture, we show that a bound on the lateral extent of the fracture can be obtained. Given the limitation on the bandwidth of acoustic logging data, we propose using the Stoneley waves generated during micro-seismic events for fracture characterization.
Date issued
2012Publisher
Massachusetts Institute of Technology. Earth Resources Laboratory
Series/Report no.
Earth Resources Laboratory Industry Consortia Annual Report;2012-02
Keywords
Fractures