Seismic Attribute Analyses and Attenuation Applications for Detecting Gas Hydrate Presence

Identifying gas hydrates in the oceanic subsurface using seismic reflection data supported by presence of a bottom simulating reflector (BSR) is not an easy task, given wide range geophysical methods that have been applied to do so. Though BSR attributed attenuation response, as waves transition from hydrate-filled sediment within hydrate stability zone (GHSZ) free gas-bearing below, few studies direct measurement. To improve detection and associated features, including accumulation beneath hydrates, we apply recently developed method known Sparse-Spike Decomposition (SSD) directly measures estimating quality factor (Q) parameter. In addition performing attribute analyses frequency attributes spectral decomposition imaging, comprehensive analysis three methods, make several key observations. These include following: (1) low-frequency shadow zones seem correlate with large values attenuation; (2) there strong relationship between amplitude strength increase response; (3) resulting interpretation migration pathways measurement method; (4) for analyzed, themselves give rise either impedance or anomalies fully differentiate them nearby non-hydrate zones. From this last observation, find that, although SSD may detect situ same often form effective seal trapping deeper accumulation, which can exhibit allowing us infer likely overlying themselves.