Drilling wells in Antarctica using a heat transfer medium
The relevance of the work is determined by the need to improve the technology of drilling deep wells in glaciers. The need for drilling in Antarctica to solve geological problems noted in the Development Strategy of the Russian Federation in Antarctica for the period up to 2020 and for a more distant perspective, approved by the Government of the Russian Federation in 2010. Taking into account the existing experience of drilling deep wells on Arctic and Antarctic glaciers by the staff of the Well Drilling Department of the Mining University and the existing infrastructure of the Russian Antarctic Expedition, the most expedient and effective for studying the subglacial Lake Vostok will be the use of the 5G well drilled at the Vostok station, where research is being conducted aimed at the technology of opening and maintaining the well in working condition during the study of the lake The East. This will allow not only to obtain absolutely unique information on various scientific disciplines, but also to a considerable extent strengthen the prestige of our country in Antarctic research. The objects of research are the technology of drilling deep wells in ice (central Antarctica). The environmental requirements imposed on drilling operations are of particular importance, since the consequences of environmental impact in polar regions with a unique combination of natural conditions can be catastrophic and irreversible. The use of traditional technical means when drilling deep wells in the ice of Antarctica is ineffective. To date, all the developed methods of drilling ice, depending on the nature of its destruction at the bottom, can be divided into thermal, mechanical and thermomechanical. The purpose of the work is a theoretical analysis of the method of drilling with a hot coolant, which should ensure the exit of a deep well (depth of 2000-4000 meters) into subglacial bedrock, and this article presents the results of calculations of the temperature regime of the well, at which the well will or will not freeze. Analysis of the current state of the technology of drilling wells in glaciers indicates low efficiency and high accident rate when penetrating deep horizons of glacial covers, which are characterized by an increase in the size of crystals and the presence of temperatures close to the melting point of ice. There are no generally accepted recommendations on the choice of rational parameters for drilling such ice at the moment. Insufficient reliability of the drilling process often led to the most severe consequences of accidents in the well - grabbing of drilling shells.