The interest in hard-to-recover hydrocarbon reserves has recently increased significantly, which is primarily due to the need to maintain the level of oil production in the late stage of development. Since all relatively large oil fields in Republic of Tatarstan have been identified and developed, in the last decade, the process of exploration extra-heavy oil deposits, whose reserves are enormous, has been rapidly developing. The object of the study is extra-heavy oil reservoir of the Kamyshla Beds of the Kazanian Stage, confined to the Gorskoye field, located in the marginal part of the Eastern side of the Melekess depression, near its junction with the western slope of the South Tatar arch. At the same time, the location of the field within the outer side zone of the Ust-Cheremshan trough of the Kama-Kinel trough system predetermined the significant influence of sedimentation processes on its formation. In order to establish the genesis, time of formation of the trap and Gorskoye extra-heavy oil deposit, the authors constructed a series of structural maps, carried out studies by methods of isopachic triangle and graph of structure growth. Paleotectonic reconstructions of the studied territory at various stages of ontogenesis allowed us to establish that the core of the Gorsky structure is an organogenic structure of Late Frasnian age, the growth of which was resumed repeatedly until the Early Kazanian age. The formation of the Gorskoye extra-heavy deposit occurred in the Late Permian age, and as a result of tectonic movements of the Alpine stage of tectogenesis, the deposit finally formed and began to collapse.
References
1. Muslimov R.Kh., Abdulmazitov R.G., Khisamov R.B. et al., Neftegazonosnost' Respubliki Tatarstan. Geologiya i razrabotka neftyanykh mestorozhdeniy (Oil and gas bearing of the Republic of Tatarstan. Geology and development of oil fields), Kazan': FEN Publ., 2007.
2. Tektonicheskoe i neftegeologicheskoe rayonirovanie territorii Tatarstana (Tectonic and oil geological zoning in Tatarstan): edited by Khisamov R.S., Kazan': FEN Publ., 2006, 328 p.
3. Mirchink M.F., Khachatryan R.O., Gromeka V.I. et al., Tektonika i zony neftegazonakopleniya Kamsko-Kinel'skoy sistemy progibov (Tectonics and oil and gas accumulation zones of the Kama-Kinel system of troughs), Moscow: Nedra Publ., 1965, 214 p.
4. Mashkovich K.A., Metody paleotektonicheskikh issledovaniy v praktike poiskov nefti i gaza (Methods of paleotectonic research in the practice of prospecting for oil and gas), Moscow: Nedra Publ., 1976, 221 p.
5. Neyman V.B., Teoriya i metodika paleotektonicheskogo analiza (Theory and methodology of paleotectonic analysis), Moscow: Nedra Publ., 1984, 80 p.
6. Otmas A.A., Complex paleotectonic analysis of conditions of forming the local objects prospective for oil: an example from the Kravtsovskoye field (In Russ.), Neftegazovaya geologiya. Teoriya i praktika, 2010, no. 5, pp. 1–12.
7. Larochkina I.A., Geologicheskie osnovy poiskov i razvedki neftegazovykh mestorozhdeniy na territorii Respubliki Tatarstan (Geological foundations of prospecting and exploration of oil and gas fields in the territory of the Republic of Tatarstan), Kazan: GART Publ., 2008, 210 p.
8. Voytovich E.D., Gatiyatullin N.S., Tektonika Tatarstana (Tectonics of Tatarstan), Kazan: KTU Publ., 2003, 132 p.
9. Produktivnye bituminoznye tolshchi permskikh otlozheniy Melekesskoy vpadiny i Tatarskogo svoda (The productive bituminous strata of the Permian deposits of the Melekess Basin and the Tatar Arch): edited by Troepol'skiy V.I., Lebedev N.P., Kazan': Publ. of Kazan University, 1982, 103 p.
10. Luk'yanova R.G.,
