Microclinoform structure of the BT₁₀ horizon as a factor controlling the formation of gas fields in the southeastern part of the Yamalo-Nenets Autonomous Okrug

The microclinoform model of the Neocomian shelf reservoirs is becoming more and more supported by practicing geologists, since it allows to effectively address the problems arising in the development of complex reservoirs. According to modern concepts, the microclinoform structure is due to the intense progradation of delta complexes during periods of forced regression. The article demonstrates the effectiveness of the microclinoform concept in building a geological model of an accumulation in BT₁₀ horizon of Zapadno-Chaselsky field, which is located in the southeastern part of the Russko-Chaselsky large swell in the southeast of the Yamalo-Nenets Autonomous Okrug. The microclinoform structure of the target was mapped based on the data volume of the second derivative of the wave field, which is more sensitive to changes in thicknesses, and porosities of sand reservoirs. As a result of comprehensive studies, correlation profiles and a GDE map of stratigraphic unconformity (top of BT₁₀) were built reflecting the microclinoform structure of the target. The results were used to build a model of a gas reservoir and estimate its reserves. Hydrocarbon discoveries have already been made in the BT group of reservoirs at Zapadno-Chaselsky field and neighboring Yuzhno-Russkoye field that improves the potential of this interval within the southeastern part of the Yamalo-Nenets Autonomous Okrug. This poses the task of its more detailed study based on the microclinoform concept.

1. Trushkova, L. Ya., Egoshkin, V. P., & Hafizov, F. Z. (2011 Neocomian Clinoforms - unique type of petroleum reservoirs of Western Siberia. St. Petersburg, VNIGRI Publ., 125 p. (In Russian).

2. Aukhatov, Ya. G. (2008). Vliyanie nadvigovykh dvizheniy na kharakter stroeniya produktivnykh plastov Tevlinsko-Russkinskogo mestorozhdeniya (Srednee Priob'e). Geology. The bulletin of the department of earth sciences and natural resources of the academy of sciences of the Republic of Bashkortostan, (12), pp. 52-53. (In Russian).

3. Aukhatov, Ya. G. (2014). Mikroklinoformnaya model' stroeniya produktivnogo plasta BS₁₀^2-3 Tevlinsko-Russkinskogo mestorozhdeniya (Srednee Priob'e, Zapadnaya Sibir'). Virtual'nye i real'nye litologicheskie modeli. Materialy 10-go Ural'skogo litologicheskogo soveshchaniya: 75-letiyu Instituta gelogii i geokhimii UrO RAN posvyashchaetsya, Ekaterinburg, October, 21-22, 2014). Ekaterinburg, Institut geologii i geohimii im. akademika A. N. Zavarickogo UrO RAN Publ., рр. 22-24. (In Russian).

4. Gachegov, A. V., Potryasov, A. A., Kostyleva, T. Yu., & Shaikhutdinov, A. N. (2004). Izuchenie geologicheskogo stroeniya plasta BS₁₀^2-3 na Severo-Konitlorskoy i Seve-ro-Kochevskoy ploshchadyakh s tsel'yu otsenki perspektiv neftenosnosti. Bulletin of the Perm State Technical University. Oil and gas, 3(5), pp. 135-141. (In Russian).

5. Ivanov, D. N., Mikheev, Yu. V. (2007). The mechanism of constructing a three-dimensional geological model of clinoform deposits of the BV10 formation of the Mykhpayskaya area of the Samotlor deposit. Proceedings of the tenth scientific and practical conference "Ways to realize the oil and gas potential of KhMAO-Yugra". Khanty-Mansiysk, 2, pp. 398-405.

6. Grischenko, A. S., Gilmanova, R. Кh., Mustaeva, E. R., & Ryzhov, S. L. (2009). Geological structure peculiarities of layer BV₁₀^1-2 local clinoforms of samotlor field. Geology, geophysics and development of oil and gas fields, (9), pp. 18-23. (In Russian).

7. Mustaeva, E. R., & Grischenko, A. S., Ryzhov, S. L., & Yarullin, R. R. (2010). Specification of geological structure of BV₁₀^1-2 formation by means of clinoform correlation method. Geology, geophysics and development of oil and gas fields, (7), pp. 50-54. (In Russian).

8. Varlamov, S. N. & Ukhlova, G. D. (2009). "Microwedge-form" structure model of shallow-sea deposits (Central part of West-Siberian flag). Burenie i neft', (9), pp. 13-14. (In Russian).

9. Catuneanu, O., Galloway, W. E., Kendall, Ch. G. St. C., Miall, A. D., Posamentier, H. W., Strasser, A., & Tucker, M. E. (2011). Sequence stratigraphy : methodology and nomenclature. Newsletters on Stratigraphy, 44(3), рр. 173-245. (In English). DOI: 10.1127/0078-0421/2011/0011

10. Ivanova, L. N., Lapina, L. V., Lebedev, M. V., & Yanevits, R. B. (2012). Principled facies model of a sedimentary basin of the clinoform type. Oil Industry, (10), pp. 7-11. (In Russian).

11. Endalova, Yu. V., Malygina, O. S., & Yankova. N. V. (2012). Microclinoform model of valanginian deposits in the Vostochno-Urengoiskoye field. Oil Industry, (10), pp. 24-27. (In Russian).

12. Korochkina, N. S. (2016). Specialty of shelf layer BS8 seismo-geological subsurface model building of Upper-Salym field. Russian Geophysic, (4), pp. 15-21. (In Russian).

13. Bushueva, Yu. Yu., Prohoshin, A. S., Shevelev, S. S., & Panyak, S. G. (2017). Update of the concept of shelf reservoirs geological-geophysical structure. Uspekhi sovremennoy nauki, 2(8), pp.164-168. (In Russian).

14. Meledin, A. S. & Belkina, V. A. (2018). Geological structure of the BV10-11 horizons by the complex of field-geologic data. Oil and Gas Territory, (1-2), pp. 32-38. (In Russian).

15. Druchin, V. S., Kasatkin, V. E., Lagutina, S. V., Grishkevich, V. F., Gilmanova, N. V. Dolmatova, S. S., & Moskalenko, N. Yu. (2016). Justification of geological models of deposits of the Imilorskoye field. Geologiya i neftegazonosnost' Zapadno-Sibirskogo megabasseyna (opyt, innovatsii): materialy desyatoy Mezhdunarodnoy nauchno-prakticheskoy konferentsii (posvyashchennoy 60-letiyu Tyumenskogo industrial'nogo universiteta), November, 24, 2016. T. 1: Geologiya, geofizika. Gidrogeologiya, geotermiya i geokriologiya. Ekologiya, promyshlennaya bezopasnost'. Tyumen, pp. 96-100. (In Russian).

16. Druchin, V. S. Khasanov, R. N., Shalamova, V. I., & Osipenko, A. S. (2017). Identification of zonal clay cap rocks in Imilor deposit of Achimovsky stratum. Geology, Geophysics and Development of oil and gas fields, (9), pp. 5-10. (In Russian).

17. Druchen, V. S. (2019). Utochnenie geologicheskogo stroeniya neantiklinal'nykh zalezhey nefti na mestorozhdeniyakh Shirotnogo Priob'ya na osnove kontseptual'nykh modeley. Avtoref. diss. … kand. geol.-mineral. nauk. Tyumen, 19 p. (In Russian).

18. Еrshov, S. V. (2018). Sequence stratigraphy of the Berriasian-Lower Aptian deposits of West Siberia. Geology and geophysics, 59 (7), pp. 891-904. (In English). DOI: 10.15372/GiG20180711

19. Baldin, V. A., Igoshkin, V. P., Mynasypov, N. Z., & Nizamutdinova, I. N. (2020). Problems and methods of stratification (as exemplified by Jurassic-Cretaceous sediments in northeastern West Siberia), Russian Geophysics, (3), pp. 17-30. (In Russian).