Inclied Cable Seismic Data Processing Technique Applied In One Block Of South China Sea

Targeted in a deep-water block in South China Sea, this paper is analyized and researed based on feature of variable-depth streamer(VDS) data, developing the seismic data processing technique and resolving difficulties of VDS data processing, which can promote the quality of deep-water seismic exploration data and acquire broadband seismic data conducive to more deeply and complicated structure imaging. Meanwhile, this paper is conducted to research of VDS data correction with method of wavefiled extrapolation which lay the foundation of successive of VDS data processing.Results and acknowledges based on research as follows:(1)Hydrophone with shallow depth of inclined streamer received high-requency data and hydrophone with deep depth of inclined streamer received low-requency data, these data contain diversity of Notch feature which means the notch feature varies with different depth of streamers. Notch stacked in a gather, and the frequency band of residual ghost is broad.(2) Mirror data can be calculated from original seismic data with image algorithms, which meeting for the demand of relation of Maximum phase and minimum phase. Based on underground 1D velocity model, travel time at the depth of mirror data at each receiving point calculated by ray tracing technique, value according the travel time on original shot gathers, which benefit to build mirror shots data.(3) Least square inversion iterative algorithm adapted to shot data and image shot data whithin ghost can acquire optimized ghost wave filter operator which applied to deghost filtering for shot gathers within ghost. This method can eliminate the reciving cable ghost in shot domains; supply the notch energy and broden the frequency band.(4) VDS data rectification with method of wavefiled extrapolation can obtain data correction on the same level, and the effection of rectification significantly better than regular cable depth correction method.