Vestnik Otdelenia nauk o Zemle RAN VOL. 4, NZ2001, doi:10.2205/2012NZ000111, 2012

Drilling of a deep bore-hole at Vostok station (East Antarctica)

N. I. Vasiliev, A. N. Dmitriev, P. A. Blinov

St. Petersburg State Mining University, St. Petersburg, Russia.

Abstract

Drilling of a deep bore-hole 5G at Vostok station (East Antarctica) from the depth of 2755 m was carried out by electromechanical drill KEMS-132. During wintering of 40th (1995) Russian Antarctic Expedition and seasons the bore-hole was deepened from the depth of 2755 up to 3623 m.

At present the bore-hole 5G has a complicated stepwise structure. The casing with an inner diameter of 165 mm insulates the upper 120 m of the hole from permeable firn.

The drilling fluid, the mixture of kerosene and Forane F-141b as densifier, has an average density of 928 kg/m3. Its level in the hole is maintained at a depth of 40 m. The difference between the overburden pressure of ice and the hydrostatic pressure of the fluid at the bottom of the hole is estimated to be about 0.1 MPa. Accordingly, the rate of the bore-hole closure at the bottom is calculated to be less than 0.1 mm/year.

Data regarding to technology of drilling by electromechanical drill KEMS-132 (description of drilling complex, electromechanical drill, casing, stability of the bore-hole) are given.

Received 15 February 2011; published 29 February 2012.

Copyright 2012 by the Geophysical Center RAS