Аренда офисов в Мурманске

 

Главная STRUCTURE AND HYDROCARBON POTENTIAL OF EAST BARENTS AND NORTH CHUKCHI BASINS
Structure and hydrocarbon potential of east Barents and North Chukchi basins Печать E-mail

VERZHBITSKY V.E., FRANTZEN E.M., LITTLE A., SOKOLOV S.D., TUCHKOVA M.I.
TGS-NOPEC Geophysical Company, Russia, TGS-NOPEC Geophysical Company ASA, Norway, TGS Geological Products and Services, Norway, Geological Institute RAS, Russia

Here we present the synthesis of available geological-geophysical data on two largest depocenters of Russian Arctic shelf - East Barents and North Chukchi basins. They are filled by thick piles of the sediments - up to 18 km and even more. It is believed, that the sedimentation in both of the basins has started in Paleozoic (Late Devonian) time. The giant hydrocarbon potential is proven for East Barents and widely proposed for the North Chukchi basin. This study is based on the newly acquired seismic data (2005, 2006), available published material and some results of field-work observations on Northern Chukotka and Wrangel Island (2006).

Our research of East Barents Sea region is mostly based on the TGS/New Geoprojects seismic data (2005) and TGS/VBPR Geophysical Atlas of Barents Sea (2004). Eastern Barents Sea region is one of the most hydrocarbon-rich sectors of Russian Arctic shelf, where the well-known gas and gas-condensate fields were discovered: Shtokman (one of the largest discoveries in the world), Ledovoe, Ludlov, etc. (e.g., Gramberg et al., 2002; Shipilov, Tarasov, 1998). The majority of the regional HC fields and potential structures are localized within the prominent NNE-trending East Barents rift (trough), filled by up to 18-20 km thick Late(?) Paleozoic – Mesozoic sequences (Bogdanov, Khain, 1996). The trough is traced to the west from Pay-Khoy - Novaya Zemlya Early Kimmerian fold belt (and its’ foredeep) and consists of two different sedimentary basins (Southeast and Northeast), separated by Ludlov Saddle. The timing of initiation of the trough formation is still a matter of discussion. It is proposed, that the Khibiny-Kontozero extensional fault zone on the Kola Peninsula, with most extensive alkaline magmatism event in the Late Devonian (timing of rifting initiation?), ~360-380 Ma (Sharkov, 2002), represents the SW onshore propagation of East Barents rift (Baluev, 2006; Leonov et al., 2007). Major subsidence of the trough took place during Late Permian and, mostly, Triassic, accompanied by voluminous terrigenous sedimentation (Shipilov, Tarasov, 1998; Shipilov, 2003). It is believed, that two major magmatic events influenced the East Barents trough in Mesozoic. First, Permian/Triassic, is considered to be synchronous with Siberian traps magmatism and second, dated in Ludlov offshore well, corresponds to the Late Jurassic-Early Cretaceous time (Shipilov, Tarasov, 1998).

These events caused the intrusion of numerous basaltic sills and dikes, intruded mostly into Upper Permian-Triassic strata and recognizable on seismic records as high-amplitude prominent anomalies. Large vertical motions, probably associated with Late Jurassic-Early Cretaceous magmatism, likely formed the regional base Cretaceous unconformity (BCU), overlain by progradational sequences (Geophysical Atlas…, 2004). The main hydrocarbon accumulations are related to gently folded Triassic, Jurassic and, to a lesser extent, Cretaceous units. It is interesting to note, that the 3D geothermal modeling has revealed the positive dome-shaped thermal anomaly, associated with the main regional hydrocarbon fields in the Southwestern Barents Sea (Podgornykh, Khutorskoy, 2000). The origin of the fold structures is still controversial. Shipilov (1998) related the folding to magmatic sills intrusion expanding influence on the above strata. According to another point of view, formation of the contractional domes was caused by far-field effect of Paleogene right-lateral transpressional movements between Greenland and Svalbard during opening of Nowegian-Greenland sector of North Atlantic (Geophysical Atlas…, 2004).

The U.S. Arctic Alaska region is famous for large oil and gas discoveries (Prudhoe Bay, Kuparuk River, Burger, etc), whereas, the geologically equivalent region in Russian territory is still poorly explored (e.g., Orudzheva et al., 1999; Mazarovich, Sokolov, 2003; Burlin, Shipelkevich, 2006; Khain, Polyakova, 2007). The Russian sector of the Chukchi Sea includes several regional tectonic subdivisions, from south to north: Chukotka (Late Kimmerian) fold belt, South Chukchi Basin (K2(?)-Cz), Wrangel (Wrangel-Herald) Arch Kimmerian, and the North Chukchi Basin. Wrangel Island, the uplifted block of the arch, is mostly composed of intensively deformed Precambrian metamorphic rocks and Paleozoic-Triassic sedimentary sequences, probably subjected to Early Carboniferous magmatism (Kos’ko et al., 1993; 2003). Thus, the Island is the key area for onshore investigation of the geological structure of Russian Chukchi Sea shelf. During summer of 2006, field works by International Russian-USA-Swedish expedition (S.Sokolov, M.Tuchkova, E.Miller, V.Pease and V.Verzhbitsky) were carried out in the Central, Western and Southern parts of the Island (Pease et al., 2007; Sokolov et al., 2007). The geological complexes of Wrangel arch are overthrusted to the North on the much lesser deformed North-Chukchi sedimentary basin, which is underlain by Mid-Paleozoic (Franklinian) basement (Khain, Polyakova, 2007).

It is likely, that the lowest part of the sedimentary cover contains Upper Devonian (?)-Carboniferous sediments, as it proposed for the Hanna trough (Sherwood et al., 2002). The maximum Pz-Mz-Cz sediment thickness of the North Chukchi basin exceeds 16 km. During the autumn of 2006, TGS conjointly with “Geophysical Solutions Integrator”, acquired new seismic data in the Russian part of the Chukchi Sea. Due to the absence of offshore wells in the Russian sector, interpretation of the seismic data is quite speculative. Several major angular unconformities were recognized on the seismic lines. These are used to delineate the tectonic mega-sequences, compare to the U.S. sector and onshore Chukotka and Wrangel Island. The deepest unconformity (LCU), identifiable in the North Chukchi basin, may correspond to the main collisional stage completion in Late Neocomian, and the beginning of orogen-derived clastic molasse sedimentation equivalent to Brookian sequences of Aptian-Albian – Cenozoic age. This boundary also corresponds to the well-known pre-Aptian unconformity of northeastern Eurasia, related to Eurasia/Chukotka collision (e.g. Sokolov et al., 2002; Katkov et al., 2007).

The Ellesmerian (D3-J3) and Rift mega-sequences (J3-K1) (Sherwood et al., 2002) may be indentified below this boundary. The most obvious unconformity in the upper part of sediments may correspond to the Mid-Brookian, MBU (~K/Cz), reported earlier for this area by (Grantz et al., 1990) and (Burlin, Shipelkevich, 2006). The shallowest identifiable angular unconformity is not very well-known here. We speculate, that it may be as old as 24 Ma related to a compressional event (latest Late Oligocene), reported for Brooks Range and Colville basin (O'Sullivan et al., 1997; Moore et al., 2002), but unknown for Chukotka/Wrangel area. The proposed age for this unconformity doesn’t contradict with pre-Miocene inversion (transpression?) occurring in the South-Chukchi basin. The wide-spread anticline structures in Paleozoic, Mesozoic and, to a lesser extent, Cenozoic sequences, provide ample structural traps. Wedge-outs, unconformities, deltaic/progradational units and potential fault traps, are also abundant. These features are often associated with “bright spot” seismic anomalies and gas chimneys, point to the significant regional hydrocarbon prospectivity (Verzhbitsky et al., 2008). According to the lithological-geochemical investigations on Wrangel Island, Carboniferous and Triassic sedimentary successions were activated as oil-generating units in the geological past.

The Carbonate formation of Carboniferous age, appears to be similar in lithology with the Lisburne formation in Alaska, where it represents one of the producing units of the Prudhoe Bay oil field (Khain, Polyakova, 2007). It is likely, that Ellesmerian strata and, probably, Jurassic-Lower Cretaceous sediments immediately to the north from Wrangel Arch are moderately deformed, and relatively shallow. Thus, the buried northern slope of Wrangel Arch may be quite prospective, as mentioned above sequences represent main producing units of Arctic Alaska. In
summary, the described structural pattern and the widely proposed similarities in geological history with Arctic Alaska, point to the significant hydrocarbon potential of the North Chukchi basin.

The participants of the International geological expedition-2006 are very grateful to Director and scientific staff of Wrangel Island National Reserve for their help on organization and carrying out of the field works. The Arctic research of the authors from Geological Institute RAS was supported by RFBR # 08-05-00547 grant and ONZ RAS.

Literature
Baluev A.S. Geodynamics of the Riphean Stage in the Evolution of the Northern Passive Margin of the East European Craton // Geotectonics. 2006. Vol. 40, No. 3, p. 183-196.
Bogdanov N.A., Khain V.E. (eds.). Explanatory notes to the International Tectonic Map of the Barents Sea Region (Scale 1:2500000), Moscow: ILOVM RAS. 1996, 94 p.
Бурлин Ю.К., Шипелькевич Ю.В. Основные черты тектонического развития осадочных бассейнов в западной части шельфа Чукотского моря и перспективы их нефтегазоносности // Геотектоника. 2006. № 2. С. 65–82.
Geophysical Atlas of Barents Basin - Integrated Seismic, Gravity and Magnetic Interpretation (edited by Planke S., Myklebust R., Falaide J.I., and Breivik A.). Copyright 2004 by Volcanic Basin Petroleum Research (VBPR) and TGS-NOPEC. Edition 1.01. Olso, June 2004. 150 p.
Gramberg I.S., Suprunenko O.I., Tanygin I.A., et al. An unique Shtokman gas-condensate field (Barents Sea) // The Russian Arctic: geological history, mineragenesis, environmental geology (Chief editors D.A.Dodin and V.S.Surkov). SPb, VNIIOkeangeologia. 2002. P. 660-663 (in Russian).
Grantz A., Johnson L., and Sweeney J.F. (eds.). The Geology of North America, vol. L, The Arctic Ocean Region // Geol. Soc. of Am., Boulder, Colo. 1990. 644 p.
Katkov S.M., Strickland A., Miller E.L., Toro J. Ages of granite batholiths from Anyui-Chukotka Foldbelt // Transactions (Doklady) of the Russian Academy of Sciences/Earth Science Section. 2007. Vol. 414, No. 4. P. 515-518.
Khain V.E., Polyakova I.D. Sedimentary Basins and Prospects of Oil and Gas Deposits on the Shelf of the Eastern Arctic // Oceanologyю 2007. Vol. 47, No. 1, p. 104-115.
Kos’ko M.K., Avdunichev V.V., Ganelin V.G. et al. The Wrangel Island: geological structure, mineragenesis, environmental geology // Ministry of Natural Resources of RF, All-Russia Research Institute for Geology and Mineral Resources of the World Ocean. – SPb., VNIIOkeangeologia. 2003. 137 p. (in Russian).
Kos’ko M.K., Cecile M.P., Harrison J.C., et al. Geology of Wrangel Island, between Chukchi and Siberian Seas, Northeastern Russia // Geological Surway of Canada Bulletin. 461. 1993, 102 p.
Leonov M.G., Baluev A.S., Kuz’michev A.B., et al. Tectonics of Arctic shelf of Russia in research of Geological Institute RAS // Oil, gas of Arctic. Proceedings of International scientific-practical conference (ed. Prof. V.P.Gavrilov). M.: Intercontact nauka. 2007. 352 p.
Mazarovich А.O., Sokolov S. Yu. Tectonic subdivision of the Chukchi and East Siberian Seas // Russian Journal of Earth Sciences, 2003, Vol. 5, No. 3, P.185–202.
Moore T.M., Dumitru T.A., Adams K.E. et al. Origin of the Lisburne Hills-Herald Arch structural belt: stratigraphic, structural, and fission-track evidence from the Cape Lisburne area, northeastern Alaska // in Miller E.L., Grantz A, and Klemperer S.L. (eds). Tectonic evolution of the Bering Shelf-Chukchi Sea-Arctic Margin and Ajacent Landmasses: Boulder, Colorado, GSA Special Paper 360. 2002. p.77-109.
Orudzheva, D.S., Obukhov, A.N., Agapitov, D.D. Prospects for oil and gas offshore exploration in Chukchi Sea // Oil and Gas Geology. 1999. v. 3/4, p. 28-33 (in Russian).
O'Sullivan P.B., Murphy J.M., Blythe A.E. Late Mesozoic and Cenozoic thermotectonic evolution of the Central Brooks Range and adjacent North Slope foreland basin, Alaska: Including fission track results from the Trans-Alaska Crustal Transect (TACT) // Journal of Geophysical Research. 1997. Vol.102, No. B9, p. 20,821-20,845.
Pease V., Miller E., Sokolov S., et al. The development of the Arctic Ocean // In: Rickberg S. (ed.) Polarforskningssekretariatets Arsbook (Swedish Polar Research Secretariat Yearbook) 2006. Stochholm: Polarforskningssekretariatet. 2007. P. 78-84.
Podgornikh L.V., Khutorskoy M.D. 3-D thermal model of the Barents-Kara region // The Russian Arctic: geological history, mineragenesis, environmental geology (Chief editors D.A.Dodin and V.S.Surkov). SPb, VNIIOkeangeologia. 2002. P. 184-192 (in Russian).
Sharkov Ye.V. Magmatic suites of the Baltic Shields above the Circle (the Cola Peninsula) // The Russian Arctic: geological history, mineragenesis, environmental geology (Chief editors D.A.Dodin and V.S.Surkov). SPb, VNIIOkeangeologia. 2002. P. 267-278 (in Russian).
Sherwood, K.W., Johnson, P.P., Craig, et al. Structure and stratigraphy of the Hanna Trough, U.S. Chukchi Shelf: in Miller, E.L., Grantz, A., and Klemperer, S.L. (eds.), Tectonic Evolution of the Bering Shelf-Chukchi Sea-Arctic Margin and Adjacent Landmasses: Boulder, Colorado, Geological Society of America Special Paper 360. 2002. p. 39-66.
Shipilov Ed.V. Interference of Tectonic-Geodynamic Regimes in Permian-Triassic Evolution of the Arctic Periphery of North Eurasia // Transactions (Doklady) of the Russian Academy of Sciences/Earth Science Section. 2003. Vol. 393A, No. 9, p. 1215-1220.
Shipilov Ed.V., Tarasov G.A. Regional Geology of Oil and Gas Bearing Sedimentary Basins of the Russian West-Arctic Shelf // Apatity. Russian Academy of Sciences. Kola Science Centre. Murmansk Marine Biological Institute. 1998. 306 p. (in Russian).
Sokolov S.D., Tuchkova M.I., Verzhbitsky V.E. Wrangel Island: a natural geology reserve // in A.R.Gruzdev (ed.). The Nature of Wrangel Island: contemporary researches. SPb. 2007. P. 254-266.
Verzhbitsky V., Frantzen E., Savostina T., Little A., Sokolov S.D., Tuchkova M.I. The Russian Chukchi Sea shelf // GEO ExPro. 2008. Vol. 5, No. 3. P. 36-41 (full article available at https://www.geo365.no/TGS-Chukchi/). 

OIL AND GAS OF ARCTIC SHELF 2008

busy
 

Добавить комментарий

Защитный код
Обновить

Язык сайта:

English Danish Finnish Norwegian Russian Swedish

Популярное на сайте

Ваш IP адрес:

54.80.237.123

Последние комментарии

При использовании материалов - активная ссылка на сайт https://helion-ltd.ru/ обязательна
All Rights Reserved 2008 - 2017 https://helion-ltd.ru/

@Mail.ru Яндекс.Метрика
Designed by Helion LTD