MODELING OF SEISMIC BLANKING ZONE FOR GAS HYDRATE
SUN Chun yan 1, ZHANG Min yu 2, NIU Bin hua 2, HUANG Xin wu 2 (1. Faculty of Engineering, China University of Geosciences, Beijing 100083, China; 2. School of Geophysics and Information Technology, China University of Geosciences, Beijing 100083, China)
The blanking zone is an important seismic indicator of gas hydrate sediment. From three kinds of micro model for hydrate sediment we chose the amplitude ratio method for measuring the blanking degree to be used in modeling and analyzing the sediment with constant and variable gas hydrate concentration, respectively. Seismic models were designed to synthesize the seismic response under these two circumstances, and the seismic blanking zone was observed. The results demonstrate that the variable gas hydrate concentration is the main cause of the amplitude blanking. There are multiple interpretations for the sediment structure with variable porosity and concentration; therefore, extra available information should be used to study and interpret the cause and the characteristics of the blanking zone.