Shallow drilling on the Taimyr Peninsula and on the shelf of the Eastern Arctic Seas of Russia

Abstract

The article reviews shallow (engineering geological, stratigraphic and prospecting) drilling in different years and using different methods. In the Arctic zone under conditions of lower temperatures and great ice cover of seas, shallow drilling was usually carried out from the shore ice in the regions of the Taimyr and Chukotka, and in the straits of the Novosibirsk Islands. Drilling from ice was implemented in the late spring–early summer at the convenient thickness and stability of the ice cover. Two wells were drilled off a drilling ship in the Laptev Sea. Moreover, two drilling expeditions were undertaken to the Laptev Sea and Chukchi Sea; those holes were drilling from non-drilling ships, using a multi-trip drilling facility. Shallow drilling enables solving important problems connected with research and production, namely, stratigraphic, paleographic, mapping and prospecting research of the upper sedimentary cover. Since the 1970s such problems were handled using various drilling techniques. Nearby the Taimyr Peninsula, drilling operations were concentrated Pyasina Bay, Mikhailov Peninsula, Fjord Gafner bay and in the Theresa Clavenes Bay. In the Laptev Sea, drilling was implemented at the Cape Mamontov Klyk, at the Lena River estuary, in the Buor-Khaya Bay and northwest of the Kotelny Island. Prospecting drilling on local islands, in bays and straits enabled comprehensive investigation in the zones of the Novosibirsk Islands. The coastal areas of the East Siberian Sea and Chukchi Sea were investigated in prospecting drilling off ice. In the Long Strait between Chukotka and the Wrangel Island, two holes were drilled from a deep-sea tug. It was determined that the upper sedimentary cover layers belong to the Paleogene–Neogene period in the straits of the Novosibirsk Islands and in shallow water of the East Siberian Sea, to the Pliocene–Quaternary period on the soundings of the Chukchi Sea and in the straits and fjords of the Taimyr, and to the Late Pleistocene–Holocene system in the Laptev Sea. Further drilling activities are aimed to find shallow placers, to study degradation of submarine permafrost and to determine gas content of sedimentary deposits. The drilling results will be used in reconstruction of the Late Cenozoic Paleogeography in the Arctic zone.The study was supported by the Russian Foundation for Basic Research, Grant No. 18-5-60004.