Biostratigraphic characteristics of Paleozoic sedimentary series of the West Taimyr potential oil and gas bearing area according to drilling data

Background. The Paleozoic sedimentary rocks of the Enisey-Khatanga oil and gas bearing region remain one of the most poorly studied depositional sequences from the margin of the Siberian craton so far. Gazpromneft is now conducting geological exploration in the western part of the region, in the area of Enisey Bay. In 2021 the first exploration well was drilled here. The well penetrated the Paleozoic series up to the Middle Ordovician deposits.
Aim. The goal of this work is to present the results of biostratigraphic studies based on the new materials of drilling.
Materials and methods. Core from well served as the basic material for the production of representative complexes of fossils. Traditional laboratory methods were used to extract fossils from sedimentary rocks and study them. All available regional data were attracted to determine the taxonomic position of fossils and their stratigraphic significance.
Results. The Darriwilian Stage of the Middle Ordovician, the undivided Sandbian and Katian Stages of the Upper Ordovician, the Telychian and Homerian Stages of the Lower Silurian, the Emsian Stage of the Lower Devonian are distinguished in the section of first exploration well as a result of conducted research. Complexes of fossils (conodonts, graptolites, Ostracoda) are given for each of the listed stratigraphic subdivisions.
Conclusions. The age of the Paleozoic units was determined as a result of biostratigraphic analysis. The stratigraphic position of regional seismic reflectors have also been clarified. Previously existing ideas about the stratigraphic structure of the Paleozoic series of the West Taimyr potential oil and gas bearing area have been significantly adjusted.

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