Vol 66 Iss. 1

In recent years, the work of the department has been characterized by a shift away from multitasking. This is explained by the establishment of more stable relations with large customers, lengthening the terms of contracts. The amount for which contracts are concluded annually is about 140 thousand rubles. All this favorably affected the results of the department.

The rate of penetration in hard rock drilling depends on the geometric shape of cutters. The penetration process when drilling hard rocks with a cylindrical crown with sharpened cutters of plate form was first considered by E. F. Epstein.

The paper considers the basic solution of the sinking rate problem based on the theoretical provisions stated earlier. The solution is based on the constancy of the cutter contact area during drilling time, on the division of the depth of the contact area introduction into two parts - upper and lower.

The first solutions to the problem of drilling with simultaneous freezing of passable rocks, which is reduced to finding the relationship between the depth of the freezing front and the mechanical speed of drilling, are approximate and contain parameters determined from “experience" or arbitrarily.

The regularities of the temperature regime of boreholes and mine workings, especially in conditions of changes in the aggregate state of the surrounding rocks, are described by extremely complex analytical expressions. The concepts of the coefficient of unsteady heat exchange k_τ and the coefficient of heat exchange intensification at the aggregate transition k_agr.

When drilling through perennially frozen rocks the same flushing fluids can be used, which are usually used in rocks with positive temperatures. All requirements for flushing agents in these conditions apply to media designed for operation at negative temperatures.

At the Department of Technology and Techniques of Well Drilling of the Leningrad Mining Institute, studies of mixtures of surface-active agents (surfactants) have been carried out. The purpose of the experiments is to obtain more effective in comparison with used single surfactant active additives.

One of the first priorities in Antarctica is to study the ice covering the continent. This article provides some thoughts on the possibility of using transportable equipment requiring relatively low energy costs in core drilling in Antarctica. Mechanical destruction of ice is supposed to be carried out with the help of a special design crown reinforced with iris-cutters made of hard alloy. The sludge formed during ice destruction will be carried out from under the end face of the crown by the flow of cleaning agent, which can be air, kerosene or paraffinic diesel fuel.

Prospective reserves of coquina phosphorite deposits in Estonia and the Leningrad Region are estimated at 2-3 billion t. Genetically, they are associated with the thickness of quartz-obol sandy sediments of the Pakerort horizon of the Early Ordovician, spread over almost the entire territory of Estonia and stretching 320 km to the east of it (Leningrad Region). The thickness of the productive strata varies from 1-6 m, with an average thickness of 4 m. Phosphorite-bearing sandy sediments with erosion lie on sandstones, siltstones or clays of Cambrian.

Modern scientific and technological progress requires more and more complete utilization of natural resources. Along with the use of other types of energy and fuel, geothermal resources, i.e. the heat content of the Earth's crust, represent an important energy reserve. Necessary prerequisites for the wide practical development of these resources creates the development of technology and technology of drilling wells, contributing to the study of ever deeper horizons of the Earth's crust and the accumulation of factual material on geothermy.

The main factors determining the peculiarities of drilling technology for high-temperature water are the increased values of reservoir pressure, gas saturation and water temperature. Depending on the magnitude of the geothermal gradient and the depth of drilling, the temperature in the well can vary widely and reach 200°C and more.

Exploration of the Tyrnyauz deposit, carried out on the flanks mainly by means of mining and drilling operations, is complicated not only by specific features of the highlands, but mainly by thick (from 50 to 180 m) deluvial-moraine deposits. These sediments are represented by unconnected fragments of altered rocks of different hardness and abrasiveness: mudstones, siltstones, tuff-sandstones, granite-gneisses and hornblende of various compositions. In addition, on the northern slopes of the ridge there are widespread areas of permafrost, which makes the specifics of drilling operations close to the conditions of the Far North.

In the existing standard (normals) of the tubular assortment of exploration drilling equipment drill string and casing pipes have dimensions that differ significantly from those of drill pipes. Recently, in connection with the transition to drilling exploration wells with removable core receivers, drill pipes are approaching the outer diameter of core pipes.

The main task of exploration of offshore deposits, as well as the deposits occurring on land, is to determine the quantity, quality and conditions of mineralization. Specificity, due to the location of the mineral deposit under the water column at different depths, in different climatic zones, makes it necessary to search for new ways and technical means of exploration.

Standard tungsten-cobalt carbide bonds, depending on their hardness and purpose, are produced by cold (No. 3, 20-25 HRC, and No. 4, 30-35 HRC) and hot (No. 5, 50-55 HRC) pressing methods. Temperatures of sintering of bond-matrixes vary in the range from 1150 (No. 3) to 1350°C (No. 5) and in a reducing medium do not lead to the appearance of noticeable traces of graphitization. or loss of mechanical strength in perfect single crystals of natural diamond.

In the process of drilling, heat is generated in the bottom-hole zone due to mechanical work of the rock-destroying tool. As a result, the natural temperature and aggregate state of frozen rock cores is disturbed. Studying the mechanism of frozen rock core thawing during drilling, finding out the regularities of the thawing process for conscious regulation and normalization of its temperature regime is of practical importance.