T.E. Ermolova, I.A. Mushin, A.A. Stupak, B.K. Frolov, G.A. Oksman,
N.Yu. Kholmyanskaya
 
Opportunities for new oil and gas bearing objects prospecting in the Upper Tournaisian-Visean terrigenous formations of eastern part of Volga-Urals Petroleum Province on the basis of integrated sedimentological and geoseismic studies
DOI 10.31087/0016-7894-2019-3-67-85

Petroleum potential of polyfacies Upper Tournaisian-Visean terrigenous rock association in the eastern regions of Volga-Urals Petroleum Province are focused on prospecting of stratigraphic and combination types of traps. Such an approach is especially relevant for depressions in the pre-Urals Foredeep; ill-defined structural factor, area reduction, and complicated morphology of terrigenous series distribution are typical of them. Substantiation of prospects in the regional stage reduces to identification and mapping of zones having different structure of the deposits, which responds to depositional environments and processes, and also lithological objects — prospective hydrocarbon traps. Updating structure of each horizon and building the respective maps is based on integration of lithofacies, sedimentological, and geoseismic analyses, including interpretation of synthetic regional seismic cubes generated using 2D seismic data. Using the thickness map of the series, boundaries of main paleotectonic zones of eastern regions of Volga-Urals petroleum region are updated. References of section structure are developed, and geological and geophysical characteristics of lithological objects having different genesis is presented. Parameters of total and net thickness, porosity, shale/sand ratio are calculated, and isopach maps are created for sands within the horizons. Seismic facies are identified, which are fitted to reference well columns both on 2D seismic time sections and in the slices of regional synthetic paleo-cubes at the levels better matching to the intervals of target horizons (Kos’vinsky-Radaevsky, Bobrikovsky, and Tul’sky). As a result of integrated analysis in accordance with references accepted for different depositional zones, structural maps and maps of promising zones of lithological objects in Kos’vinsky-Radaevsky, Bobrikovsky, and Tul’sky formations are created. Promising zoned of lithological objects associated with the deposits of onshore (subaerial) channels within fluvial distributary systems, subaqueous delta front fans, and bars are identified. According to interpretation of 2D seismic data and regional cubes, zones of search for new exploration targets associated with submarine extension of paleochannels and sandy fans to the marine part of sedimentary basin are delineated.

 

Key words: Volga-Urals Petroleum Province; pre-Urals Foredeep; Kamsky-Kinel’sky system of troughs; Tournaisian-Visean terrigenous formation; reservoir rocks; synthetic regional cubes; stratigraphic and combination traps.

For citation: Ermolova T.E., Mushin I.A., Stupak A.A., Frolov B.K., Oksman G.A., Kholmyanskaya N.Yu. Opportunities for new oil and gas bearing objects prospecting in the Upper Tournaisian-Visean terrigenous formations of eastern part of Volga-Urals Petroleum Province on the basis of integrated sedimentological and geoseismic studies. Geologiya nefti i gaza = Oil and gas geology. 2019;(3):67-85. DOI: 10.31087/0016-7894-2019-3-67-85.

References

1. Stashkova E.K., Stukova T.V., Pakhomov V.I. Correlation of polyfacies deposits: an example of the Visean terrigenous series. Problemy mineralogii, petrografii i metallogenii: sb. nauch. st. 2003. Issue 5. pp. 128–136.
2. Stukova T.V. Palynological characteristics of the Tournaisian-Viséan terrigenous deposits of Permian Prikamie. Lethaea rossica. Rossiiskii paleobotanicheskii zhurnal. 2012;6:32–45.
3. Pakhomov V.I., Pakhomova I.V. Visean coal-bearing formation in the western slope of Middle Urals and pre-Urals. Moscow: Nedra; 1980. 153 p.
4. Pyatunina E.V., Khakimova Zh.A., Neganov V.M. Features of reservoirs development in the Visean terrigenous series and opportunities for their discovery in the south-east of Permian Kama region. Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdenii. 2007;(10):27–31.
5. Mushin I.A., Fortunatova N.K., Belousov G.A. Technologies of construction of the volume sediment-capacity models of sedimentary basins. Tekhnologii seismorazvedki. 20012;(1):37–45.
6. Alekseev A.S. Exploration maturity of pre-Cambrian and Phanerozoic stratigraphy in Russia. Objectives of further research. Regulations of interagency commission on stratigraphy and its standing committees. Postanovleniya mezhvedomstvennogo stratigraficheskogo komiteta i ego postoyannykh komissii. St. Petersburg: Izd-vo VSEGEI; 2008. Issue 38. pp. 61–68.
7. Ermolova T.E. Clinoform structure of Radayev-Elkhov deposits of Kama-Kinel system of troughs and problems of revealing non-anticlinal traps. Geologiya nefti i gaza = Oil and gas geology. 2005;(5):15–23.

T.E. Ermolova

All-Russian Research Geological Oil Institute, Moscow, Russia

ermolova@vnigni.ru

I.A. Mushin

All-Russian Research Geological Oil Institute, Moscow, Russia

mushin@vnigni.ru

A.A. Stupak

All-Russian Research Geological Oil Institute, Moscow, Russia

stana@vnigni.ru

B.K. Frolov

All-Russian Research Geological Oil Institute, Moscow, Russia

frolov@vnigni.ru

G.A. Oksman

All-Russian Research Geological Oil Institute, Moscow, Russia

g_oksman@vnigni.ru

N.Yu. Kholmyanskaya

All-Russian Research Geological Oil Institute, Moscow, Russia

natahol@vnigni.ru