* The Achimovsky strata are located in the lower part of Cretaceous (chalk) deposits almost directly above the oil-bearing Bazhen Formation (strata in Western Siberia, lying at a depth of two to three kilometres). The Achimovsky strata occur throughout the central zone of the West Siberian basin, with the thickest strata found in the Nadymsky and Purovsky Districts of the Yamal-Nenets Autonomous Okrug. The Achimovsky strata are characterised by a complex geological structure, necessitating the use of technologically complex techniques in their development.
Various geological models have been developed by the Science and Technology Centre since 2007, with approximately 30 substantive models having been produced at various times, including areas within Russia and abroad, both onshore and offshore, and of varying extent, detail and area of focus (for example, on the Bazhen Formation exclusively). The Science and Technology Centre utilises a range of proven, modern methodologies and technologies based on geophysical approaches and data, as well as more progressive computer-modelling techniques (seismic-geological, sedimentary and basin research). The trend in recent years — and which distinguishes the new model — is the use of Big Data analysis techniques, together with machine learning. The creation of unique “digital twins” of fields, strata or oil-or gas-bearing basins makes it possible to improve accuracy and efficiency in both geological prospecting and subsequent asset development.