3D seismic acquisition at a Rosneft’s gas field in Krasnoyarsk region is characterized by difficult hydrographic conditions. Use of standard technological solutions is problematic due to the wide Angara River, which does not freeze during winter period. The article describes the methodology for 3D seismic acquisition using water and ground sources, geophones, marshphones and hydrophones. The methodology allows to maintain a regular survey network throughout the study area and, as a result, to receive good quality seismic data within the river region. In the article, 3D seismic survey design was described in detail. Then, the technology of producing and receiving of seismic signals by pulsed electromagnetic sources was considered. After that, the stage of quality control of the fieldwork results was presented. Seismograms, obtained on land and water, were processed using the unitized workflow in the integrated project. The processing workflow comprised noise reduction in various data sorting, regularization by offsets with a variable panel width. Finally, several iterations of the mesh migration calculation were performed for refinement of the velocity model for migration. The workflow results in preserving the wave pattern characteristics over the entire area and obtaining high-quality data for structural and dynamic interpretation. Measures, described above, improve the productivity, stability and quality of the obtained seismic data. The technology can be successfully applied in shallow water (depth less than 15 m) and transition zones to extend study survey areas by regions, which were unreachable due to the complex hydrography of Eastern Siberia.
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