Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

In order to study gas hydrate, possible new energy resources, KIGAM has performed seismic reflection survey over the East sea since 1999. The evidence for the existence of gas hydrate in seismic reflection data is the BSR (bottom simulated reflection) which parallels the sea bottom. The BSR has high amplitude reflections, the amplitude above the BSR increase and the interval velocity below the BSR decrease. However, since high amplitude reflections are also shown in free gas and sediments bearing silica, we need to find out the difference from these. In this study we performed conventional data processing for gas hydrate data and seismic complex analysis which has been using for detecting gas layers. We made reflection strength profile, its first and second-derivative profiles, instantaneous phase profile and instantaneous frequency profile. The reflection strength profile shows instantaneous amplitude difference at the strong BSR layer (SP 2100-2600, TWT 3.4 s). In the instantaneous phase profile, phase changes around the possible BSR layer, but we could not find the cross-cutting at the overlying and underlying of a gas bearing zone, which would be parallel reflection to the sea bottom. For the instantaneous frequency profile, frequency changed from high to low around the BSR layer.