AN ACOUSTIC IMPEDANCE INVERSION APPROACH TO DETECT AND CHARACTERIZE GAS HYDRATE ACCUMULATIONS WITH SEISMIC METHODS: AN EXAMPLE FROM THE MALLIK GAS HYDRATE FIELD, NWT, CANADA ...

Two internationally-partnered research well programs, in 1998 and 2002, studied the Mallik gas hydrate accumulation in the Mackenzie Delta, Canada. Gas hydrate bearing intervals were cored, logged and production tested thus establishing Mallik as an excellent site for testing geophysical imaging tec...

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Bibliographic Details
Main Authors: Bellefleur, Gilles, Riedel, Michael, Mair, Stephanie, Brent, Tom
Format: Text
Language:English
Published: The University of British Columbia 2008
Subjects:
Online Access:https://dx.doi.org/10.14288/1.0041051
https://doi.library.ubc.ca/10.14288/1.0041051
Description
Summary:Two internationally-partnered research well programs, in 1998 and 2002, studied the Mallik gas hydrate accumulation in the Mackenzie Delta, Canada. Gas hydrate bearing intervals were cored, logged and production tested thus establishing Mallik as an excellent site for testing geophysical imaging techniques. Here, we apply a model-based acoustic impedance inversion technique to 3D seismic reflection data acquired over the Mallik area to characterize gas hydrate occurrences and to help define their spatial extent away from well control. Sonic logs in Mallik research wells show that P-wave velocity of sediments increases with hydrate saturation, enough to produce detectable reflections for the lower two of three known gas hydrate zones. The inversion method converts these reflections into acoustic impedances from which velocity and hydrate saturation can be estimated. Acoustic impedance inversion results indicate that the deepest gas hydrate zone covers an area of approximately 900,000 m2. With some assumptions ...