Characterizing 3D fracture networks and modeling wave propagation beneath Southern Hydrate Ridge using data from the existing 3D seismic site survey

使用现有 3D 地震现场勘测数据表征 3D 裂缝网络并模拟南部水合物海脊下方的波传播

• 批准号: 0646226
• 负责人: Anne Tréhu
• 金额: $ 8.93万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-15 至 2010-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0646226&HistoricalAwards=false
• 关键词: Characterizing; 3D; fracture; networks; modeling

The proponents will mine 2-D seismic data collected in 2000 from Hydrate Ridge to better define the fracture networks and conduits beneath the summit region that are involved in transporting gas into and through the gas hydrate stability zone. Tasks to be undertaken to achieve this goal include 1) incorporation of a deterministic static correction to prestack seismic reflection data to correct for changes in water depth due to tides; 2) a different approach to binning and interpolating the prestack data to improve north-south continuity of slices through the seismic data; 3) construction of a 3D velocity model that integrates results from OBS travel-time tomography, VSPs, and sonic logging; 4) 3D pre-stack depth migration of the tide-corrected and interpolated reflection data; and 5) forward modeling of the wavefield using finite difference synthetic seismograms of individual shot and midpoint gathers to better understand amplitude affects due to seafloor scattering and separate them from those due to attenuation in the subsurface.The potential broader impacts of this project include providing important background information needed for planning several large programs that are currently under development. It will also provide training for a promising young female post-doc. The 3D images of the subsurface plumbing of an active seafloor vent system will also be useful for transmitting the excitement of this research to the general public.

支持者将挖掘2000年从水合物脊收集的二维地震数据，以更好地定义顶部区域下的裂缝网络和管道，这些裂缝网络和管道涉及将天然气输送到天然气水合物稳定带并通过天然气水合物稳定带。为实现这一目标，需要承担的任务包括：1)结合叠前地震反射数据的确定性静校正，以校正潮汐引起的水深变化；2)采用不同的叠前数据分块插值方法，提高地震数据的南北连续性；3)综合OBS走时层析成像、VSPs和声波测井结果构建三维速度模型；4)潮汐校正和插值反射数据的叠前三维深度偏移；5)利用单个炮点和中点地震集的有限差分合成地震图对波场进行正演模拟，以更好地了解海底散射对振幅的影响，并将其与地下衰减对振幅的影响区分开来。该项目潜在的更广泛的影响包括为规划目前正在开发的几个大型项目提供重要的背景信息。它还将为一名有前途的年轻女性博士后提供培训。活跃的海底喷口系统的地下管道的三维图像也将有助于向公众传播这项研究的激动人心之处。