SEGJ Technical Conference

Self-organizing map using attenuation measurements from sonic waveform data

Abstract The method of evaluating reserve of Methane hydrate by using the characteristic that its layer is high speed layer is known. Also, its layer is known as high attenuation layer, but using it for evaluation is under discussion. First in this study, we used the method described in article written by Guerin and Goldberg published in 2002 to estimate Q at Nankai trough to check up its effectivity in evaluating the reserve and checked its high attenuation at hydrate layer. Second, we checked correlation between high speed layer and high attenuation layer by examining the relation between its Q and speed. Finally, we tried the classification by using self-organizing map. First, we used sonic velocity, resistivity, and Gamma ray as parameters and classified them according to self-organizeing map. Next, we added Q to parameters and classified them once again and checked differences between first classification and second it.