APPLICATION OF SEISMIC DETECTING TECHNIQUE TO MARINE GAS HYDRATE SURVEY

Gas hydrate, popularly known as "flammable ice", is an ideal energy characterized by high energy density, wide distribution, shallow burial, simple forming condition and clean developing environment. It may become a new energy source to replace oil and gas in the future. There are favorable gas hydrate forming conditions in the deep water of the China Seas, such as the abundance of sources, combination of temperature and pressure and geo-structures, and thus there is great resource potential.The seismic detecting technique is an effective method in marine gas hydrate survey, which has been widely applied in many deep water areas in the world. China has recently developed by itself the seismic detecting techniques for marine gas hydrate survey, including the seismic identification and processing techniques (i.e. the real amplitude processing, zero-phasing of wavelet, precise velocity analysis etc.) and the seismic attribute distilling techniques (i.e. seismic AVO analysis and quantified simulation, wave impedance inversion, the coherent body detection, and calibration and identification of gas hydrate stability zones etc.)The seismic signs of gas hydrate such as Bottom Simulating Reflector (BSR), Blank Zone (BZ), Velocity Inversion (VI) and Reversal Polarity (RP) have been found in the continental slope of northwestern South China Sea by using the seismic detecting techniques mentioned above. Based on the seismic anomalies, drilling testing has been made and gas hydrate samples have been successfully obtained in the region. This paper focuses on the current status of development and application of seismic exploration technology for marine gas hydrates survey in China, with a brief introduction to the status overseas.