The objective of this work was to study the autigenic mineralization, its stages, and its influence on the reservoir properties of terrigenous reservoirs in the northern part of the Nepa-Botuoba anteclise. It is based on the core material of deep well sections with contrasting reservoir properties. A special influence on the reservoir properties of the rocks was exerted by the autigenic mineralization, manifested both in the pore and fractured space. In the fractured zones, such minerals as phlogopite, barite, sphalerite, pyrite with an admixture of arsenic compounds, chalcopyrite, rhodochrosite, sanidine, analcime, celestine, cuboargyrite, calcite, dolomite, magnesite, anhydrite, halite. The presence of these mineral parageneses indicates the active development of hydrothermal processes in the productive deposits of the Vendian. A sequential change of regenerative quartz cement to carbonate, sulfate, and halite cements in the pore space was revealed. The autigenic mineralization shown in reservoir rocks significantly reduces the reservoir properties and prevents both vertical and lateral fluid migration. The porosity of reservoir rocks located at a distance from hydrothermal mineralization zones can reach 20%, and the permeability is 1 mkm2. Class II and III reservoirs will be distributed in such zones. The porosity of reservoir rocks located near hydrothermal mineralization zones does not exceed 15%, and the permeability is 0,250 mkm2. Class III and IV reservoirs will be distributed in such zones. The void space of the Vendian terrigenous reservoir rocks of the Nepa-Botuoba anteclise is the result of a multi-stage change of mineral parageneses formed at the stages of regional background lithogenesis of immersion, as well as due to a complex combination of local superimposed types of lithogenesis, especially hydrothermal-metasomatic.
2. Fomin A.M., Dan'kina T.A., Distribution of reservoir rocks in oil and gas horizons in the northeastern part of the Nepa-Botuobinskaya anteclise (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta, 2010, V. 316, no. 1, pp. 57–61.
3. Plyusnin A.V., Conceptual model sedimentological Botuoba productive horizons of Srednebotuobinskoye oil and gas condensate deposit (In Russ.), Vestnik VGU. Seriya: Geologiya, 2019, no. 2, pp. 61–69.
4. Kosachuk G.P., Burakova S.V., Butochkina S.I. et al., On the formation of oil deposits (rims) of the Nepa-Botuobinskaya anteclise (In Russ.), Vesti gazovoy nauki, 2013, no. 5(16), pp. 114–123.
5. Akulov N.I., Vallev R.R., Peculiarities of the Srednebotuobinsk oil-and-gas deposit geological structure (In Russ.), Izvestiya Irkutskogo gosudarstvennogo universiteta. Seriya: Nauki o Zemle, 2016, V. 18, pp. 3–13.
6. Postnikov A.V., Postnikova O.V., Iz"yurova E.S. et al., Evolution of the processes of mineral formation in Early Vendian terrigenous rocks of the Nepa–Botuoba anteclise (In Russ.), Litologiya i poleznye iskopaemye = Lithology and Mineral Resources, 2019, no. 1, pp. 31–43.
7. Zoloeva G.M., Postnikova O.V., Iz"yurova E.S. et al., The prediction of salinization Lower Vendian terrigenous reservoir rocks of Nepsko-Botuobinskaya anteclise (In Russ.), Geofizika, 2019, no. 2, pp. 8–15.8. Khanin A.A., Porody-kollektory nefti i gaza neftegazonosnykh provintsiy SSSR (Reservoir rocks of oil and gas of the USSR petroliferous provinces), Moscow: Nedra Publ., 1969, 368 p.