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Sparkers are the sound source widely used in marine seismic exploration to provide high-resolution vertical sections. Sparkers are relatively simple, inexpensive, high-frequency sources. In this study, the types of noise occurring in sparker source data were analyzed and attenuated by a processing technique. Frequency–wave number (f–k) filtering is used for attenuating the linear noise. Predictive deconvolution is used for attenuating the ghost waves and bubble effects. A complete processing workflow was designed for processing the data, and the migration section was obtained. The results show that the sparker source data are capable of achieving vertical sections with very high resolution. It is suggested as a necessary technique for high-accuracy gas hydrate exploration in the South China Sea.

Vertical cable seismic (VCS) is a kind of reflection seismic exploration technique. Multi-node hydrophone array set perpendicular to the seabed and records wave field inspired by air gun. Vertical cable seismic exploration can make up for the disadvantages of the harsh conditions of towed cable seismic exploration. VCS technique is also convenient to be used in monitoring the underground geologic changes in the stage of gas hydrates development. In this paper, VCS data collected near the gas hydrates test and mining area of the South China Sea was processed and obtained multi-wave imaging profiles. It is shown that the VCS data has such advantages as high signal-to-noise ratio, high fidelity, and so on compared to the towed cable data, especially in the imaging of underground steep dip angle geological structures.

Amplitude versus offset (AVO) contains abundant information of sediment elastic properties. Some of these properties are sensitive to the saturation of gas hydrate or free gas accumulated in the sediments. Here, AVO inversion is performed to the seismic data of Shenhu Area, South China Sea. Based on the accurate Zoeppritz equation, P wave velocity and S wave velocity are obtained. Based on elastic impedance equation, P wave impedance, S wave impedance, and fluid factor are obtained. The inverted elastic parameters show that there are gas hydrate and free gas in this area. Moreover, the conception of elastic parameters relative variation rates was proposed and applied here, and the results show that they can be used to identify the top of gas hydrate zone.