Collaborative Research: Seismic Characterization of a Gas Hydrate System in the Gulf of Mexico-A Novel Approach to Evaluate High-Resolution Wide-Angle Data

在USGS的一个联合项目中，密西西比大学和美国能源部从墨西哥湾天然气水合物环境中收集了单通道地震和海底地震仪数据。初步结果显示，含有水合物的泥底辟下有游离气，但没有模拟海底的反射层(BSR)。私人投资促进机构建议进一步开发现有的地震层析成像代码，以自洽的方式处理反射界面和转换后的横波。该代码最初将应用于墨西哥湾密西西比峡谷地区一个有趣的天然气水合物问题。这项新技术将被用来了解：1)浅层水合物在海底下面延伸了多远？2)浅层水合物下面是否存在游离气，如果存在，是什么圈闭？3)为什么不存在BSR。对已有的三维数据进行优化处理，提出一种基于层析反演的三维PS-NMO方法。

In a joint project USGS, University of Mississippi and the DOE gathered single-channel seismic and ocean bottom seismometer data from the Gulf of Mexico gas hydrate environment. Initial results show free gas beneath a hydrate-bearing mud diapir but lacks a bottom-simulating reflector (BSR). The PIs propose to further develop an existing seismic tomography code to handle reflecting interfaces and converted shear waves in a self-consistent way. The code will be initially applied to an interesting gas hydrate problem from the Mississippi Canyon area in the Gulf of Mexico. The new technique will be used to learn: 1) how far does the shallow hydrates extend beneath the seafloor?, 2) does free gas exist beneath shallow hydrates and if so, what traps it?, 3) why is there no BSR present. The existing 3D data will be optimized and a method will be developed for 3D PS-NMO based on tomographic inversion.