The results of exploration of Rosneft’s license areas in the Irkutsk region for 10 years

UDK: 550.81
Key words: Eastern Siberia, Nepsko-Botuobinskaya anteclise, oil reservoir, Ust-Kut horizon, basement, exploration
Authors: Ya.I. Gordeev (Rosneft Oil Company PJSC, A.V. Gaiduk, A.V. Mityukov (RN-Exploration LLC, RF, Moscow), A.V. Filichev (Verkhnechonskneftegas PJSC, RF, Irkutsk)
The article is dedicated to the history of geological exploration carried out by Rosneft Oil Company in Irkutsk region. The article covers key milestones, main problems encountered in the process of geological exploration as well as achieved results. Currently, the Company owns rights to mineral extraction from 10 license blocks. For over 5 years of exploration activities, the Company has booked hydrocarbons reserves produced from several fields, but within the fields of Irkutsk region no natural flow of hydrocarbons have been observed. All the discoveries were associated with tight reserves. Only in 2011 a drilled well showed natural flow of oil from a fundamentally new type of prospects of Ust-Kut horizon, which had not been previously considered as a highly promising. That was a beginning of a new approach in geological exploration - prospecting for better quality reservoir zones among hydrocarbons accumulations associated with tight reserves (the concept of «sweet areas»). Presently, all wells drilled in the prospects identified based on the new concept have been successful (natural flow of hydrocarbons after drilling). High-quality 3D seismic acquisition not only confirmed the available discoveries, but also helped to identify new prospects, including Osinsky horizon and clastic sediments. The article describes how, by changing a geological concept and, therefore, a strategy of geological exploration, the company managed to drill wells with naturally flowing oil and gas, made discoveries with traditional HC reserves and raised a share of successful drilling to 75%.
References
1. Gayduk A.V., Al'mendinger O.A., Formation conditions and criteria for prediction
of areas of improved reservoir properties ancient Vendian-Cambrian
reservoirs (for example, Danilovskiy license area (East Siberia)) (In Russ.),
Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft'”, 2013, no. 1, pp. 10-13.
2. Gayduk A.V., Kashirina E.G., Red'kin N.A. et al., Regularities of development
of perspective objects in carbonate Vendian-Cambrian sedimentary cover
of the southern Siberian platform (In Russ.), Nauchno-tekhnicheskiy vestnik
OAO “NK “Rosneft'”, 2016, no. 3, pp. 28-31.
3. Gayduk A.V., Fomin A.E., Tverdokhlebov D.N. et al.,Oil and gas prospective
facilities identification in the subsalt carbonate complex of Nepa-Botuoba
anteclise as a result of historical 2D seismic data reprocessing and reinterpretation
(In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft'”, 2016,
no. 3, pp. 44-48.
4. Gayduk A.V., Mityukov A.V., Filichev A.V. et al., Vyyavlenie perspektivnykh i
vysokoproduktivnykh zalezhey UV v drevnem vend-rannekembriyskom osadochnom
chekhle Nepsko-Botuobinskoy anteklizy na osnovanii interpretatsii
sovremennykh geofizicheskikh dannykh (Identification of perspective and
highly productive hydrocarbon deposits in the ancient Vendian-Early Cambrian
sedimentary cover of the Nepa Botuoba anteclise based on the interpretation
of modern geophysical data), Proceedings of IV International scientific
and practical conference “Geobaykal – 2016”, 22-26 August 2016, Irkutsk.
5. Fomin A.E., Batishcheva A.M., Gayduk A.V., Filichev A.V., Vydelenie perspektivnykh
v neftegazovom otnoshenii ob"ektov v podsolevom karbonatnom
intervale razreza Nepskogo svoda Nepsko-Botuobinskoy anteklizy po
dannym seysmorazvedki 2D i 3D (Selecting the potential gas and oil objects
in the pre-salt carbonate interval of Nepa arch of the Nepa Botuoba anteclise
according to 2D and 3D seismic surveys), Proceedings of IV International
scientific and practical conference “Geobaykal – 2016”, 22-26 August
2016, Irkutsk.
6. Tverdokhlebov D.N., Korobkin V.S., Dan'ko E.A. et al., Konechno-raznostnoe
seysmogeologicheskoe modelirovanie s tsel'yu povysheniya effektivnosti
obrabotki i kachestva interpretatsii seysmicheskikh dannykh (Finite difference
seismic and geological modeling to improve the efficiency of processing
and interpretation of seismic data), Proceedings of IV International scientific
and practical conference “Geobaykal – 2016”, 22-26 August 2016, Irkutsk.
7. Red'kin N.A., Gayduk A.V., Petrov A.N., Ustanovlenie zakonomernostey
rasprostraneniya kollektorov v drevnikh vendskikh terrigennykh otlozheniyakh
Nepsko-Botuobinskoy anteklizy na osnove skvazhinnykh i seysmicheskikh
dannykh (Determination of laws of propagation of collectors in ancient Vendian
terrigenous deposits of the Nepa Botuoba anteclise based on borehole
and seismic data), Proceedings of IV International scientific and practical
conference “Geobaykal – 2016”, 22-26 August 2016, Irkutsk.


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