«Proceedings of Gubkin University»

Tectonics of southwestern part of oil-and-gas-perspective zone radial fault within Sverdlovsk Ring Megastructure as inferred from seismic survey data

UDC: 550.311
DOI: -

Authors:

¹ Bulashevich Institute of Geophysics, Ural Branch of the Russian Academy of Sciences, Yekaterinburg, Russian Federation
² Zavaritsky Institute of Geology and Geochemistry, Ural Branch of the Russian Academy of Sciences, Yekaterinburg, Russian Federation

Keywords: Sverdlovsk Ring Megastructure, petroleum potential, geological and geophysical studies, seismic surveying, tectonic faults/discontinuities, hydrocarbon fields, Buzuluk depression, Caspian depression, magnetic anomalies, Sladkovsko-Zarechnaya area, Yasnopolyanskaya area, rhombic fault network

Annotation:

The article examines the tectonic structure of the southwestern part of the presumed radial fault of the Sverdlovsk Ring Megastructure and its influence on the localization of oil and gas fields in the region. The fault zone is associated with hydrocarbon deposits in the Devonian graben-like troughs of Bashkortostan, the Manchazh, Orenburg, and Tashla magnetic anomalies, and the Shalkar seismically active zone in Kazakhstan. 2D and 3D common midpoint (CMP) seismic surveys conducted in the Sladkovsko-Zarechnaya and Yasnopolyanskaya areas within the Orenburg Oblast, and the subsequent interpretation of the data, allowed for a detailed characterization of the deep structure and petroleum potential of these areas. Tectonic processes, including neotectonic ones, have significantly influenced the geological structure and petroleum potential of the region. The identified structures are confined to a rhombic fault network, which coincides with the directions of the ring and radial faults of the megastructure. Tectonic disturbances have been identified in the basement rocks, subsalt and suprasalt deposits; however, no faults have been recorded within the salt sequence itself, which is likely due to their “healing”. The identified deformations appear as numerous combinations of horsts and grabens on the seismic time sections, hydrocarbon deposits being confined to flower structures. It is concluded that the northeastern-striking radial fault of the Sverdlovsk Ring Megastructure significantly influences the tectonics and petroleum potential of the study area. However, hydrocarbon fields are more closely associated with its ring faults.

Bibliography:

1. Danilova E.A. Sverdlovskaya radial’no-koncentricheskaya struktura – centr akkumulyacii uglevodorodov v zone sochleneniya plit // Trudy Rossijskogo gosudarstvennogo universiteta nefti i gaza imeni I.M. Gubkina. – 2024. – № 2 (315). – S. 14–25.
2. Staroverov V.N., Tregub A.I., Matveev V.V. Novaya tochka zreniya na proiskhozhdenie devonskih grabenoobraznyh progibov v predelah Volgo-Ural’skoj NGP // Nedra Povolzh’ya i Prikaspiya. – 2013. – № 75. – S. 3–15.
3. Shapiro B.A. Ostatochnaya namagnichennost’ – prichina Manchazhskoj regional’noj magnitnoj anomalii // Dokl. AN SSSR. – 1981. – T. 259, № 6. – S. 1339–1344.
4. Fedorova N.V. Issledovanie anomalii vekovogo hoda geomagnitnogo polya v observatorii Arti i na Manchazhskom poligone // Ural’skij geofizicheskij vestnik. – 2005. – № 1 (7). – S. 61–69.
5. Ogadzhanov V.A., Maslova M.Yu., Ogadzhanov A.V. Oshchutimye zemletryaseniya Volgo-Prikaspijskogo regiona i ih tektonicheskaya poziciya // Nedra Povolzh’ya i Prikaspiya. – 2013. – № 74. – S. 71–83.
6. Trofimov V.A. Glubinnye regional’nye sejsmorazvedochnye issledovaniya MOGT neftegazonosnyh territorij. – M.: GEOS, 2014. – 202 s.
7. Senchina N.P., Asoskov A.E. Rekonstrukcionnyj podhod k interpretacii sdvigovyh struktur po geofizicheskim dannym // Nedropol’zovanie XXI vek. – 2023. – № 5-6 (101). – S. 50–57.
8. Danilova E.A. Solyanye struktury osadochnogo chekhla Russkoj platformy kak otrazhenie vozmozhnyh geodinamicheski aktivnyh ochagov generacii uglevodorodov v fundamente (na primere Orenburgskoj oblasti) // Geologiya i geofizika yuga Rossii. – 2021. – T. 11, № 3. – S. 33–44.
9. Ivanova N.A., Safonov A.O. Osobennosti stroeniya galogennyh tolshch zony sochleneniya Prikaspijskoj vpadiny i Volgo-Ural’skoj anteklizy na territorii Orenburzh’ya // Nedra Povolzh’ya i Pri-kaspiya. – 2010. – № 61. – S. 33–41.
10. Golov A.A., Mohnatkin V.A. Perspektivy razvitiya poiskovo-razvedochnyh rabot na Yuzhnom pogruzhenii Buzulukskoj vpadiny v Orenburgskoj oblasti // Geologiya nefti i gaza. – 1988. – № 2. – URL: https://cyberleninka.ru/article/n/perspektivy-razvitiya-poiskovorazvedochnyh-rabot-na-yuzhnom-pogruzhenii-buzulukskoy-vpadiny-v-orenburgskoy-oblasti/viewer
11. Tyurin A.M. Vydelenie maloamplitudnyh tektonicheskih narushenij v predelah Orenburgskogo vala // Geologiya i ekspluataciya neftyanyh i gazoneftyanyh mestorozhdenij Orenburgskoj oblasti; pod red. A.S. Panteleeva, N.F. Kozlova. – Orenburg: Orenburgskoe knizhnoe izdatel’stvo, 2001. – S. 90–94.
12. Levshunova S.P., Ovcharenko A.V., Zor’kin L.M. Genezis gazov i neftej Zajkinskogo mestorozhdeniya // Geologiya nefti i gaza. – 1988. – № 2. – URL: http://www.geolib.ru/OilGasGeo/1988/02/Stat/stat13.html
13. Hristoforova N.N. Konvektivnye yachejki v mantii i teplovoj potok // Georesursy. – 2001. – № 1 (5). – S. 20–27.