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REFINEMENT OF THE STRUCTURE OF THE VILYUY HEMISYNECLISE BASED ON THE RESULTS OF REINTERPRETATION OF SEISMIC EXPLORATION

I. A. Gubin

А.А.Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, Russia

The article analyzes the deep drilling data and results of seismic CDP operations performed within the Vilyuy hemisyneclise from the 1980s to the present. Seismogeological conditions are characterized. The structural model of sedimentary cover up to the top of the Lower Cambrian is developed. 5 seismic sequences are identified, maps of their thicknesses are presented. Proveniances of Mesozoic, Permian, Carboniferous, Devonian, Silurian, Ordovician and Middle-Upper Cambrian deposits are outlined. The structure of the Vilyuy hemisyneclise sedimentary cover is shown on deep seismic-geological sections constructed on the basis of the detailed velocity model, as well as taking into account modern and retrospective geological and geophysical data. The limited development of Devonian deposits in the inner parts of the hemisyneclise is shown, where, according to modern seismic data, the Cambrian is predicted under Carboniferous deposits, and seismic facies characteristic of the Kempendyay rift zone deposits are absent in the wave fields of the pre-Permian part of the section.

Keywords: Vilyuy hemisyneclise, seismic sequence, reflecting horizon, structure map, reflection-time section, velocity model, sedimentary cover.

DOI 10.20403/2078-0575-2020-4-40-52