Impacts of SNR and shot point locations on calculation precision of ocean bottom cable azimuth
Li Peng1, Gu Hanming1, Wang Ziqiu2, Li Yanqing2
1. Institute of Geophysics and Geomatics, China University of Geosciences (Wuhan), Wuhan, Hubei 430074, China; 2. Geophysical R & D Institute, China Offshore Service Limited, CNOOC, Tianjin 300451, China
Abstract：Three-component ocean bottom cables are usually deployed by drag-and-drop approach. With the influence of ocean currents and board speeds, the azimuth of two horizontal components of sensors cannot be fully the same as the designed azimuth. In order to have the precise azimuth, azimuth deviation of two horizontal components should be calculated. This paper analyzes angular deviations under different noise levels for 2D data, and angular deviations under different azimuths and different noise levels for 3D data. In a time window of a trace, direct wave samples on X and Y components have a linear relation. Without considering the influence of azimuth factors, the azimuth deviation decreases with SNR increase. The azimuth deviation range can be calculated with a known SNR of seismic data. The azimuth deviation close to the axis direction is minimum when SNR is low. As SNR increases, the minimum azimuth deviation distracts with 45 degree angle directions from the axis.
李鹏, 顾汉明, 王子秋, 李艳青. 信噪比和炮点方位对海底电缆方位角求取精度的影响[J]. 石油地球物理勘探, 2014, 49(3): 431-436.
Li Peng, Gu Hanming, Wang Ziqiu, Li Yanqing. Impacts of SNR and shot point locations on calculation precision of ocean bottom cable azimuth. OGP, 2014, 49(3): 431-436.
