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Amplitude loss of sonic waveform due to source coupling to the medium

Geophysical Research Letters

By:
,
DOI: 10.1029/2006GL029015

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Abstract

In contrast to hydrate-free sediments, sonic waveforms acquired in gas hydrate-bearing sediments indicate strong amplitude attenuation associated with a sonic velocity increase. The amplitude attenuation increase has been used to quantify pore-space hydrate content by attributing observed attenuation to the hydrate-bearing sediment's intrinsic attenuation. A second attenuation mechanism must be considered, however. Theoretically, energy radiation from sources inside fluid-filled boreholes strongly depends on the elastic parameters of materials surrounding the borehole. It is therefore plausible to interpret amplitude loss in terms of source coupling to the surrounding medium as well as to intrinsic attenuation. Analyses of sonic waveforms from the Mallik 5L-38 well, Northwest Territories, Canada, indicate a significant component of sonic waveform amplitude loss is due to source coupling. Accordingly, all sonic waveform amplitude analyses should include the effect of source coupling to accurately characterize a formation's intrinsic attenuation.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Amplitude loss of sonic waveform due to source coupling to the medium
Series title:
Geophysical Research Letters
DOI:
10.1029/2006GL029015
Volume
34
Issue:
5
Year Published:
2007
Language:
English
Publisher:
Wiley
Contributing office(s):
Coastal and Marine Geology Program
Description:
L05303; 4 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geophysical Research Letters
Number of Pages:
4