Vol 105

The development and widespread introduction of high-speed diamond drilling into the practice of geological exploration for solid minerals requires the study of the nature of the direct interaction of the diamond drill bit with the rock, since it is here that the main factors affecting the efficiency of rock destruction and the performance of the rock-destroying tool should be sought.

The development of diamond drilling technology based on the use of high-speed modes, new rock-destroying tools and the use of low-heat-capacity cleaning agents (gas-liquid systems) makes increased demands on the performance and, first of all, on the normalization of the temperature regime of diamond rock-destroying tools.

The efficiency of diamond drilling tools is determined by the mass of bulk diamonds embedded in them. Deviation from the optimum in one or another direction leads to a decrease in drilling performance.

The drilling process is the result of two joint effects: axial force on the drill bit and rotational frequency, manifested as mechanical drilling speed and wear rate of diamond drill bit.

The development of a methodology for calculating the depth of pneumatic percussion drilling with the use of gas-liquid cleaning agent seems to be very important for the correct assessment of the possibilities of pneumatic percussion drilling and determination of rational modes of supplying gas-liquid mixture (GMS), providing the maximum energy parameters of the pneumatic percussion at minimum pressure losses in the well.

Currently, foams are used when drilling wells for solid minerals in frozen rocks, in conditions of difficult water supply, at low formation pressures in permeable, fractured and cavernous, but relatively stable rocks.

To improve the technological processes of drilling in difficult geological and technical conditions by using foam flushing systems (FFS) requires compressed gas of medium or high pressure. A new direction in the search for effective ways of obtaining FPS was the use for these purposes of compressor-compression devices (CCD), implemented on the bases of drilling pumps.

Nowadays, more and more attention is paid to the study of bottom-hole cleaning processes, especially in connection with the widespread use of various cleaning agents that cause changes in the operability of rock-destroying tools.

When drilling vertical and declined wells, the volumetric tool takes the working position under the action of its own gravity. Determination of the dependence of the resistance coefficient C_R, fluid resistance force F_C and speed of movement of the removable tool v on its weight, length, angle of inclination of the well, viscosity of the flushing fluid and the size of the annular gap was carried out on a specially made experimental stand by the method of falling weight.

The practice of exploratory drilling within the field indicates that the overwhelming number of complications and accidents during well sinking is associated with zones of argillized ignimbrites, genetically related to ore mineralization.

It is known that the content of carbonate rocks in argillites affects their stability and therefore can be used as a predictive parameter when drilling unstable, prone to collapse zones of argillites. The available chemical-analytical methods for carbonate determination are complicated and unproductive.

Application of so-called "dry" quick-setting mixtures (DSM) based on mineral binders as plugging material for isolation of zones of geological complications (cleaning agent absorption, water influxes and intervals of unstable rocks associated with them) required creation of a number of special devices for delivery and processing of DSM directly in the well interval to be plugged.

In the process of drilling and equipping hydrogeologic wells, the natural state and properties of rocks in the downhole zone are changed to a greater or lesser extent.

The study of structure formation kinetics of plugging systems from the moment of their mixing to the final strength is a very difficult task.

Drilling of wells is always accompanied to a greater or lesser extent by their curvature, which in some cases causes negative consequences and requires measures for artificial curvature by means of diverters, in other cases can be used for successful solution of geological-exploration tasks.

In order to develop a technology that meets the requirements of deep wells in thick ice strata and provides the necessary degree of stabilization of the borehole walls during drilling and exploration, it is necessary to solve a number of theoretical and experimental problems associated with the study of ice behavior in the near-wellbore space of the well.

Due to the spread of drilling operations in the most diverse geological and natural conditions, constant increase in the depth of exploration and production wells, intensification of traditional and development of new technological methods of drilling, heat and mass exchange processes occurring in the well are becoming increasingly important at all stages of well construction, and the temperature factor in many cases is becoming one of the main technological parameters, determining not only the efficiency of individual operations, but also the very possibility of the well construction.

One of the promising directions of creation and development of new complexes of high-performance technical means for drilling wells in difficult mining and geological conditions is the development of fundamentally new methods of rock destruction, differing both in the type of energy used and the nature of its transfer to the rock massif at the bottom of the well.

In order to take significant samples of liquid or gas in order to study in detail the material composition of various horizons of glacial covers, the distribution of rare or dispersed chemical elements in them, their isotopic composition, etc. in the practice of glaciological research, the method of drilling wells with melting in the sampling interval of the necessary volume of caverns is widely used.

Vostok station is located in Central Antarctica in the area of the South Geomagnetic Pole in 1410 km from Mirny Observatory. The peculiarities of Vostok station are extremely low on Earth temperatures (-89 °С) and atmospheric pressure (405-480 mm Hg), significant elevation above sea level (3488 m).

The area of use of underwater drilling equipment objectively determines the necessity of complex mechanization and automation of all links of the technological process of drilling a well.

Since the second half of 1983 at the coal fields of Vorkutinskaya GRE the KPS-300 unit has been mastered. Already drilled more than 7 thousand meters of pilot wells, the average depth of which was 110 meters, the maximum - 185 meters.