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在南卡罗来纳州大西洋沿海平原能源部的Savannah河试验场,在一个处理放射性废料大罐(直径27m)的下面,曾进行井间地震和连续记录地震测量。我们使用该资料勾划低速带(软物质)并进行井间黏土层连通性成像。在综合了岩心和测井曲线资料的井间地震层析图像上所给出的低速带,揭示了150ft~180ft之间(46m~55m)该区域的软物质,在井间地震剖面深度为180ft(55m)处观测到的反射波对应于这个低速带的底界面。这个反射与软物质和较硬的Tinker组之间的阻抗差异相符。该软物质的低速带指示出碳酸盐岩组(它是Utley石灰岩的一部分)的溶蚀边缘和Griffins Landing段疏松砂岩的存在。射线追踪和共震源地震记录表明Utley石灰岩的坚硬部分横向扩展到检波器井西边大约12.5ft(4m)。连续记录资料展示了140ft~150ft(43m~46m)之间区域里的漏泄波和简正波。漏泄波和简正波计算出的群速度等值线与基于测井和井间地震资料的波导模型是一致的。这就说明Griffins Landing段内低速的褐色黏土(隔水层组)在井之间是连通的
At the Savannah River test site at the Department of Energy’s Atlantic Coastal Plain in South Carolina, under a large radioactive waste tank (27m in diameter), well-to-well seismic and continuous seismic recordings were conducted. We use this data to map low-velocity zones (soft matter) and image inter-well clay connectivity. The low-velocity bands given on the cross-well seismic tomographic images that combine core and well logging data reveal soft matter in the region between 150 ft and 180 ft (46 m to 55 m) with a depth of 180 ft (55m) observed at the reflection of the corresponding low-speed zone with the bottom interface. This reflection is consistent with the difference in impedance between the soft material and the harder Tinker group. The slow velocity zone of the soft matter indicates the erosion margins of the carbonate group, which is part of the Utley limestone, and the presence of loose sandstone in the Griffins Landing section. Ray tracing and co-seismic seismograms indicate that the hard part of the Utley limestone extends approximately 12.5 ft (4 m) west of the geophone well. Continuous recorded data shows leakage and normal waves in the area between 140 ft and 150 ft (43 m and 46 m). The group velocity contours calculated by leakage and normal waves are consistent with the waveguide models based on log and crosswell seismic data. This shows that the low-velocity brown clay (aquitard) within the Griffins Landing segment is connected between the wells