Implication of seismic attenuation for gas hydrate resource characterization, Mallik, Mackenzie Delta, Canada
Implication of seismic attenuation for gas hydrate resource characterization, Mallik, Mackenzie Delta, Canada
复制标题
DOI：
10.1029/2007jb004976
复制
发表时间：
2007-10-30
影响因子：
3.9
通讯作者：
Dallimore, S. R.
中科院分区：
文献类型：
--
作者：
Bellefleur, G.;Riedel, M.;Dallimore, S. R.
波衰减是含水合物沉积物的一个重要物理特性，在地震数据的场地表征中很少考虑到它。我们提出了一个现场示例，显示了衰减效应补偿后地震数据上含水合物沉积物的改进图像。根据加拿大西北地区马利克获得的零偏移距垂直地震剖面数据估计的压缩质量因子表明，含水合物沉积物存在显着的波衰减。这些结果与之前从不同频率间隔的声波测井和井间数据获得的衰减估计一致。应用逆 Q 滤波器补偿永久冻土和含水合物沉积物的衰减效应，提高了表面 3D 地震数据的分辨率及其与测井数据的相关性，特别是对于最浅的天然气水合物层段。永久冻土衰减效应的补偿可能解释了浅层天然气水合物区的大部分改进。我们的结果表明，使用未校正衰减的地震数据来表征马利克天然气水合物往往会高估含水合物地层的厚度和横向范围，从而高估水合物的体积。
Wave attenuation is an important physical property of hydrate-bearing sediments that is rarely taken into account in site characterization with seismic data. We present a field example showing improved images of hydrate- bearing sediments on seismic data after compensation of attenuation effects. Compressional quality factors estimated from zero-offset Vertical Seismic Profiling data acquired at Mallik, Northwest Territories, Canada, demonstrate significant wave attenuation for hydrate-bearing sediments. These results are in agreement with previous attenuation estimates obtained from sonic logs and crosshole data at different frequency intervals. The application of an inverse Q-filter to compensate attenuation effects of permafrost and hydrate- bearing sediments improved the resolution of surface 3D seismic data and its correlation with log data, particularly for the shallowest gas hydrate interval. Compensation of the attenuation effects of the permafrost likely explains most of the improvements for the shallow gas hydrate zone. Our results show that characterization of the Mallik gas hydrates with seismic data not corrected for attenuation would tend to overestimate thicknesses and lateral extent of hydrate- bearing strata and hence, the volume of hydrates in place.