Characterization of gas hydrate systems on the Hikurangi margin (New Zealand) through geostatistical seismic and petrophysical inversion

Quantitative characterization of gas hydrate systems on continental margins from seismic data is challenging, especially in regions where no well logs are available. However, probabilistic seismic inversion provides an effective means for constraining the physical properties of subsurface strata in such settings and analyzing the variability related to the results. We have applied a workflow for the characterization of two deepwater gas hydrate reservoirs east of New Zealand, where high concentrations of gas hydrate have been inferred previously. We estimate porosity and gas hydrate saturation in the reservoirs from multichannel seismic data through a two-step procedure based on geostatistical seismic and Bayesian petrophysical inversion built on a rock-physics model for gas hydrate-bearing marine sediments. We find that the two reservoirs together host between 2.45 x 105 and 1.72 x 106 m3 of estimate provides a first-order assessment for further gas hyseismic inversion method is an effective approach for characdata.

Automated summary

The study successfully characterized the physical properties of two gas hydrate reservoirs east of New Zealand using seismic data and Bayesian petrophysical inversion methods. This approach provides a preliminary assessment and technical support for further exploration of gas hydrate resources in the region.