HR: 1340h
AN: OS23A-1050    [Abstracts]
TI: Turbidite channel as methane hydrate concentrated zone - study results of 3D seismic data interpretation -
AU: * Shimoda, N
EM: shimoda-naoyuki@jogmec.go.jp
AF: Japan Oil, Gas and Metals National Corporation, 1-2-2, Hamada, Mihama-ku, Chiba, 261- 0025, Japan
AU: Saeki, T
EM: saeki-tatsuo@jogmec.go.jp
AF: Japan Oil, Gas and Metals National Corporation, 1-2-2, Hamada, Mihama-ku, Chiba, 261- 0025, Japan
AU: Inamori, T
EM: inamori-takao@jogmec.go.jp
AF: Japan Oil, Gas and Metals National Corporation, 1-2-2, Hamada, Mihama-ku, Chiba, 261- 0025, Japan
AU: Kobayashi, T
EM: kobayashi-toshiaki@jogmec.go.jp
AF: Japan Oil, Gas and Metals National Corporation, 1-2-2, Hamada, Mihama-ku, Chiba, 261- 0025, Japan
AU: Fujii, T
EM: fujii-tetsuya@jogmec.go.jp
AF: Japan Oil, Gas and Metals National Corporation, 1-2-2, Hamada, Mihama-ku, Chiba, 261- 0025, Japan
AB: 3D seismic data were acquired in the eastern Nankai Trough area, offshore Japan by METI in 2002 in order to evaluate resource potential of methane hydrates. Through the studies on these seismic data and the results of multi-well drilling surveys carried out in 2004, more than 10 methane hydrate concentrated zones were delineated in this area. The methane hydrate concentrated zones were characterized by turbidite sand bodies which can be roughly classified into channels and lobes in the seismic geomorphology point of view. We focused our attempt to reveal internal structure of a channel type methane hydrate concentrated zone using high resolution 3D seismic data. Basically, channel complex can be recognized by reflectors suggesting erosion surfaces and internal bodies of sand layers. The whole channel is vertically divided to the upper and lower parts bounded by BSR. As it is difficult to interpret the internal structure in the lower part due to the less continuous reflectors, only the upper part was geomorphologically analyzed by picking the high amplitude reflectors which suggest the hydrate concentrated sand dominated bodies. The group of the picked reflectors suggests the 3D feature of the channel development. The channel was bended during its sediment deposition. The original channel flowed from northeast to south. And later, the flow was from northeast to west-southwest. Thus, we can find the detailed shape of each sand dominated body within channel, and therefore, it is expected that detailed analysis of many reflector patches in the channel can teach us the properties of methane hydrate bearing thin sand dominated bodies by classifying their shapes. Further, such properties will contribute to the future precise volume estimation of methane hydrates, and also to the model construction for production simulation. This study is carried out for Research Consortium for Methane Hydrate Resources in Japan (MH21).
DE: 3004 Gas and hydrate systems
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting