STRATIGRAPHIC DRILLING IN THE NORTHEASTERN LAPTEV SEA: MAIN RESULTS AND FURTHER DEVELOPMENT
N.A. Malyshev1, V.E. Verzhbitskii1, S.M. Danilkin2, A.A. Kolyubakin3, V.B. Ershova2,4,5, A.A. Borodulin1, V.V. Obmetko1, D.K. Komissarov1, M.L. Boldyrev2, I.S. Vasil’eva2, M.A. Rogov2,3, A.B. Popova2, O.S. Makhova2, V.N. Stavitskaya2, T.A. Timoshenko2, A.N. Alymov2, V.A. Shein2, A.S. Ugryumov2, V.E. Vasilev6, Yu.A. Gatovskii7, V.G. Lakeev8, R.V. Lukashev8, G.N. Aleksandrova4, A.V. Lidskaya4, A.N. Simakova4, D.A. Lopatina4, S.I. Bordunov4,7, A.A. Suslova7,8, A.V. Stupakova7,8, A.M. Nikishin7
1Rosneft Oil Company, Moscow, Russia
2Arctic Research Center, Moscow, Russia
3RN-Explorations, Moscow, Russia
4Geological Institute, Russian Academy of Sciences, Moscow, Russia
5Institute of Earth Sciences, Saint Petersburg State University, St. Petersburg, Russia
6Institute of Geology and Fossil Fuel Development, Moscow, Russia
7Lomonosov Moscow State University, Moscow, Russia
8National Intellectual Resource Foundation, Moscow, Russia
Keywords: Arctic shelf, core, hydrocarbon potential, biostratigraphy, seismic stratigraphy, rift basins
Abstract
The Russian sector of the Eastern Arctic is characterized by large basins with thick sedimentary filling, primarily on the shelf and continental slope of the seas of the Arctic Ocean. A number of geological, geophysical, and geochemical features point to a hydrocarbon potential. At the same time, the age and composition of the sedimentary infill of the shelf basins have been controversial until now due to the lack of wells drilled in the shelf area. Six stratigraphic wells were drilled with core sampling in the eastern Laptev Sea (Anisin-Novosibirsk block owned by Rosneft) with a depth of 100 to 199.5 m during the Rosneft Stratigraphic Drilling in Arctic (RoSDAr) project in 2021. The results of complex biostratigraphic studies of the core show that the oldest strata in the well sections are Upper Barremian - Lower Aptian deformed silty mudstones (folded basement assemblage) overlain with angular unconformity by sands, silts, and clays of the Paleocene. The wells also penetrate the Eocene, Oligocene, and Miocene-Quaternary clastic rocks. A comprehensive analysis of stratigraphic drilling and seismic data refines the geological models of the region and provides better understanding of its hydrocarbon potential. The data show that Cenozoic strata play a more significant role in the sedimentary cover of the Laptev Sea than was previously assumed.
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