Substantiation of methodology for integrated studies of Domanik-type formations using materials from new wells (Ukhtinsky region, Southern Timan)

The Domanik-type deposits are represented by high-carbonaceous carbonate-siliceous rocks being a member of Palaeozoic carbonate formations occurring in the east of the European part of Russia, in Volga-Urals, and Timan-Pechora Petroleum Provinces. In recent decades, they have been considered an unconventional oil system that generates and accumulates hydrocarbons, and requires a targeted study using new methods. The features of the Domanik-type series are enrichment in syngenetic organic matter, considerable inhomogeneity, membership in the class of mixed sedimentary rocks. They determined the need for a comprehensive lithological, geochemical and petrophysical study aimed at obtaining integral characteristics that would allow associating them with production logging data. Substantiation of methodology was carried out using the drilling data from five structural wells (Komi 1 to 5) up to 300 m deep. They were drilled with total coring in the Timan-Pechora Petroleum Province in the southern limb of the Ukhtinsky fold (Southern Timan), in the zone of shallow occurrence of these formations, in the vicinity of the Domanik Horizon type section on the Domanik stream and the Lylael’sky Fm type section on the Lylael’ stream; both sections contain the deposits of the Frasnian Domanik, Vetlasyansky, and Sirachoisky horizons. The purpose of drilling was to encounter the full thickness of these formations and to use the core material in lithological, geochemical, and petrophysical studies by means of modern methods with a step not exceeding 0.1 to 0.3 m. Integrated studies also included paleontological studies of the deposits encountered by wells in order to substantiate their age and update boundaries of stratigraphic units on the basis of conodont complexes and vegetal spores. Well columns are characterized by the extended well log suite including electrical logging, neutron logging, density logging, sonic logging, gamma-ray logging, caliper logging, lateral logging, acoustic image logging, sonic waveform logging, spectral gamma-ray logging, and induced spectral gamma-ray logging