New data on the structure of the Paleozoic sedimentary cover deposits in the northeast of Western Siberia

UDK: 551.733

DOI: 10.24887/0028-2448-2026-6-6-11

Key words: Western Siberia, Paleozoic, carbonate deposits, well geophysical surveys

Authors: G.L. Rozbaeva (RN-GRD LLC, RF, Tyumen); E.V. Astafyev (RN-GRD LLC, RF, Tyumen); L.A. Dubrovina (RN-GRD LLC, RF, Tyumen); O.V. Chikisheva (RN-GRD LLC, RF, TyumenG.L. Rozbaeva (RN-GRD LLC, RF, Tyumen); E.V. Astafyev (RN-GRD LLC, RF, Tyumen); L.A. Dubrovina (RN-GRD LLC, RF, Tyumen); O.V. Chikisheva (RN-GRD LLC, RF, Tyumen)

The article presents the results of studies of Paleozoic deposits in the northeastern part of Western Siberia. Based on new drilling data obtained from Vostochno-Suzunskaya well the structure of the pre-Jurassic basement within the study area was analyzed. A description of the lithological composition of the rocks from bottom core samples of the Vostochno-Suzunskaya well is provided. On the basis of extended well-logging data, a geological and geophysical interpretation was carried out for the Vostochno-Suzunskaya and Medvezhya-316 wells. The results were correlated with the stratotype (Tochinskaya-11 well) in accordance with the structural-facial zoning scheme of Paleozoic depostits of Western Siberia and with seismic data across the entire area of study. Based on core description and well-logging data carbonate deposits of various composition typical of sedimentary platform covers were identified within the study area which are represented by dolomites with individual interbeds of limestones and argillaceous dolomites. Higher up the section variously carbonatized argillaceous rocks occur, presumably shales. The Paleozoic sedimentary deposits are unconformably overlain by Lower or Middle Jurassic sediments. In order to improve the reliability of the results biostratigraphic determinations are planned. Drilling of wells penetrating the Paleozoic sedimentary cover in this area and the study of prospective carbonate deposits may enhance accuracy of the distribution of pre-Jurassic reservoirs forecast within the study area, and opens up new prospects for hydrocarbon exploration in the region.

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