Technological aspects and experience of stratigraphic drilling in the seas of the Russian Arctic

Starting from 2020, Rosneft Oil Company has launched a unique program of stratigraphic drilling in the Russian Arctic seas - RoSDAr (Rosneft Stratigraphic Drilling in Arctic). The main objective of the project is to obtain direct data on geological structure of underexplored parts of the Arctic shelf, where no exploratory and parametric drilling has been carried out before. For this purpose, key technological aspects of the stratigraphic drilling program implementation for all the Russian Arctic seas were developed. These works include integration of drilling methods, wells geophysical studies and high-frequency seismoacoustic surveys based on domestic methodological approaches and innovative equipment designed specifically for the tasks of the project. The technologies used during the project make it possible to work in hard-to-reach Arctic regions. During the project implementation (2020-2023), large-scale works were carried out in the Kara Sea north, in the Laptev, East Siberian and Chukchi seas; and unique geological material was obtained. The acquired data make it possible to resolve key geological uncertainties related to sedimentary rocks of the studied regions: age, composition, formation conditions, geochemical and geophysical parameters, elements of petroleum systems, etc. Integration of core analysis data from stratigraphic wells with the results of previous geological and geophysical works is an essential part of the project implementation, which allows us creating the most reliable models of the studied regions for a reasoned forecast of their petroleum potential, and increasing the efficiency of exploration works. The implemented program of near-surface stratigraphic drilling is one of the key milestones of the Arctic shelf geological research having not only a unique fundamental scientific, but also primary applied significance for further development of the Russian Arctic. Rosneft's project on stratigraphic drilling implemented in underexplored sedimentary basins of the Russian Arctic seas is aimed at resolving the current key geological uncertainties related to the age, composition, formation conditions and petroleum systems of sedimentary cover rocks. The new data obtained are used to create the most reliable geostructural models of the studied regions with the purpose of reasonable forecast of their oil and gas content, which in turn will result in increase in geological exploration efficiency.