Gas hydrate elastic properties inversion by AVO Technology in Shenhu Area of the South China Sea

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.