The Key Techniques of 3D Seismic Data Processing for Gas Hydrate

Gas hydrate occurs in strata under the seabed, with the characteristics of shallow buried depth and rapid lateral change. In addition, there is lots of free gas in the shallow seabed. In order to study the distribution and thickness of gas hydrates, 3D seismic acquisition technology with three sources and twelve cables was firstly used to obtain high-density 3D seismic data in the South China Sea. In order to highlight the reflection characteristics of hydrates, five-dimensional interpolation techniques are used to eliminate the acquisition footprints in the three-dimensional high-resolution data processing. And the depth-domain velocity model tomography multi-round iterative technology and Q tomography modeling technology are used to obtain high accuracy velocity model and Q model. The final Q-PSDM results profile improves the imaging accuracy of the hydrate orebody and the underlying strata, eliminates the imaging artifacts caused by gas cloud area, and lays the foundation for the interpretation of the hydrate orebody.