APPLICATION OF AVO INVERSION TO GAS HYDRATES IDENTIFICATION TO THE QIONGDONGNAN AREA, NORTHERN SOUTH CHINA SEA

AVO inversion technique was applied to identification of gas hydrate in the Qiongdongnan area, Northern South China Sea. First, the AVO attributes of gas hydrate and free gas under different stratigraphic models are simulated and analyzed. Results show that the AVO attributes characteristics of gas hydrate change with saturation. When the gas hydrate saturation is high, the AVO attributes will be characterized by negative intercept, positive gradient, negative intercept x gradient, and the negative fluid factor. When the saturation is low, however, there will be negative intercept, negative gradient, positive intercept x gradient, negative fluid factor and larger amplitude. Therefore, according to the results of forward analysis, the seismic data of the Qiongdongnan sea area are processd by AVO attributes, and upon the basis, the characteristics of AVO attributes for high saturation hydrate in this area are identified. It proves that the method has big potential in gas hydrate exploration.