The paper presents the results of borehole stability research and considers possible causes of emergencies. The features of the blast hole drilling process are analyzed taking into account the properties of the rock. Based on the distribution of speed of drill fines removal from the well, an algorithm for selecting drilling modes is proposed. The nature of change in the size of the holess over time has been analyzed. This paper investigates the influence of rock fracturing and its water content on borehole stability. Possible options for eliminating the man-made impact on the massif near holes and options for fixing the hole walls with soft shells are suggested. The experimental data on the installation of shells for the conditions of open mining of apatite-nepheline ores are given. The operability and effectiveness of the technology is proved.
The analysis of practical solutions for a joint cooperation between the Mining University and the Australian company Orica resulted in the decision of creation a Competence center in the field of mining. The role of mining engineering and vocational education as necessary components of sustainable development of the territories was highlighted. The best Russian and international experience of collaboration between technical universities and main companies-players in the mining area is analyzed; an important role belongs to the involvement of regional executive authorities in a collaboration in the field of industrial safety. The prospects for the creation of a joint integration platform for a university and a company is considered on the example of creation of scientific educational laboratory of blasting technologies and modeling; the laboratory was opened under the agreement between Saint-Petersburg mining university and Orica company with the purpose of improvement of mining engineers training in the field of blasting operations, the development of scientific and research investigation activities, the organization of professional retraining and upgrade qualifications of specialists of mining area. A set of target indicators of the effectiveness of the scientific educational laboratory performance are given, as well as a general evaluation of the cooperation project efficiency.
The basic aspects of safe mining of potash deposits is reviewed. Practical examples of the mechanism and possible consequences of violating the integrity of the waterproof rock strata are described. Use of remote non-destructive monitoring system for non-destructive integrity breeds of the waterproof rock strata is proposed.
Address the major aspects of waste disposal in underground space. Are key problems of isolation of wastes in underground salt deposits? Proposed waste disposal technology, based on the use of waste for immobilization of natural mineral salts.
Decision algorithm for rock mechanics problems for bottom layers of potash deposits is suggested. Flow chart for the algorithm and it’s parts is shown. The algorithm represents the method to choose excavation technology for multi-layer potash deposits.
An example of application of finite element method in rock mechanics is presented. Parameters of stress-and-strain state of rocks in vicinity of a shallow transport excavation are estimated. Some results of numerical modeling are presented.
The relationship between displacements of the excavation contour and distance to the excavation face is obtained in the paper. The relationship allows to calculate support pressure with the account for delay of the support installation. Some calculation results of axial forces in the support are given. Calculations are made on the basis of finite-element method with three dimensional models.
Radioactive waste received by manufacture of electric power requires a highly reliable burial place. One of the most perspective types of storehouses is underground developments in adjournment to soluble salts, created by dissolution through chinks from the surface. Existing requirements to a burial place of radioactive waste are described as key aspects of a complex method of an assessment of a mechanical condition of rocks in vicinities of chambers- storehouses in seismically active areas which are potentially suitable for storage and burial place of waste are stated.
We describe the stages in the development of the method of underground dissolution of salts from the surface through wells. Formulated the key aspects of the complex method of assessing the mechanical state of rocks in the vicinity of mining solution such as cameras located in seismically active areas of potentially suitable for storage and disposal of waste
The basic laws of gas filtration at different stages of coal deposit mining are considered. The technique used for studying complex development of power resources of coal deposits, allowing with reference to concrete conditions to receive engineering dependences for a quantitative estimation of all key parametres of investigated processes is given. On the basis of the developed approach to complex development the algorithm of the practical solution of the problem is offered.
Methods of substantiation of a rational mining technology for the new potash horizon are presented in the paper. Progressive technological mining schemes for potash mining company «Belaruskaliy» are reviewed, as well as the geological conditions of the IV potash horizon. Basic aspects of the geomechanical substantiation of parameters of technological mining schemes for conditions of the IV potash horizon in the presence of influence of the overlying horizons are also presented. Results of modeling of the stress-and-state strain of the rock strata with production horizons are described.
The growth in energy consumption demands increase in power output of the existing nuclear power plants and construction of the new ones. Radioactive waste requires high-reliable repositories to be disposed. One of the perspective types of the repositories is underground excavations in halogenous formations (created by underground mining or dissolution through boreholes from surface). The new method of radioactive waste disposal is offered in the paper.
The scheme of approach of evaluation of the stability of underground structures with account for seismic activity of rock strata is introduced. Some aspects of estimation of stability of underground structures under dynamic loads are also present. Methods of choosing the safe parameters of underground mining with account for seismic and tectonic activity of rocks are shown.
The underground extraction of deposits with coal-plough machines using for the mine destruction is the long-range outlook because of the full workflow automation. The grave disadvantage of mechanical destruction is heavy energy consumption on separation of. The authoring is evidence of the possibility of the coal-plough machines creation with a new principle of ore separation on the basis of the big debris ore break off. The principle is developed in SPMI and it’s permitted to reduce energy consumption on the ore destruction in comparison with legacy domestically produced and world-wide prototype.
The problems of development of mining education in the St. Petersburg Mining Institute are considered. The main stages of their development are considered: before the Great Patriotic War (1941-1945), during the war and in the post-war period. A brief characterization of these stages is given. Brief biographies of key figures who contributed to the successful formation of mining education at the St. Petersburg Mining Institute are given. The traditions of teaching mining engineering disciplines are revealed. Teaching traditions are based on both analytical and experimental and experimental-analytical teachers, whose knowledge is based primarily on their own industrial and scientific experience.
The issues of Russian education in the field of oil and gas production are considered, the stages of its development at the St. Petersburg Mining Institute are described. The importance of graduates of the Mining Institute - initiators of a number of scientific trends in the development of theory and practice of hydrocarbon field development - is emphasized. The stages of selection and training of specialists in the field of hydrocarbon field development in the conditions of modern society are analyzed. The interrelation of the labor market and the level of education of graduates - young specialists is considered. Training of highly qualified specialists in modern conditions is impossible without close connection of higher educational institution with industrial and scientific associations.
Improving the efficiency of hydrocarbon recovery from the subsurface largely depends on the development systems, technologies and quality of the productive strata opening. One of the methods for intensification of production and completeness of oil recovery is underbalanced drilling-in using horizontal and horizontal-branch wells. For these conditions the choice of flushing solution and regulation of its structural and rheological properties at a given level is fundamental.
The issues of drilling and construction of wells under unequal components of rock pressure in saline sediments are considered. The main factors that reduce the stability of the wellbore are given. Reflects the issues associated with the choice of the type of drilling fluid to exclude harmful manifestations of rock pressure.
The issues of laying of chambers on the brine fields of great depths are considered. The factors that have a favorable impact on the stability of underground dissolution chambers have been revealed. It is proposed to develop the reserves of dome-type deposits from depths of more than 2500 m.
The target objectives of the development of underground salt dissolution technology were and still are to increase the productivity of wells and the completeness of extraction of the deposits' reserves. The complexity of the problems of managing the process of underground salt dissolution through the wells is unique for man-made objects volumes filled with liquid. To intensify the process of solvent saturation, taking into account the above difficulties and peculiarities, the following method is proposed. Underground salt dissolution chamber is eroded by means of buried water supply. Preliminarily on the surface the solvent is saturated with carbon dioxide in the mass ratio of carbon dioxide to solvent from 0.02:1 to 0.16:1. Non-solvent is mixed with carbon dioxide absorbent in the mass ratio of absorbent to carbon dioxide from 1.1:1 to 1.5:1 and periodically fed into the chamber. Preliminary calculation of the technological schemes of salt dissolution through wells developed by the author showed that this method allows increasing the productivity of underground dissolution chambers by 10-20 %, which indicates the prospects for further development of the proposed technologies.
A brief characteristic of the Sol-Iletsk rock salt deposit is given and the main technological parameters of its mining are described. An analysis of various techniques for assessing the stability of underground dissolution chambers is performed, which showed that the use of such techniques in specific mining and geological conditions in the mining of domed deposits (by underground dissolution) does not adequately reflect the operating conditions of critical elements of the rock mass. Estimation of the stress-strain state of rocks may be done using numerical methods for solving mining-geotechnical problems: the boundary element methods, the finite element method, the finite difference method - also for mining-geological conditions of Sol-Iletsk field. Numerical solutions (based on the listed methods) quite objectively reflect the stress-strain state of salt massif in the vicinity of dissolution chambers. Modeling of technological parameters of rock salt mining by underground dissolution may be carried out by the dummy loadings method. Preliminary calculations by the mentioned method, carried out for the already worked out sections, give a rather high convergence of the calculated and observed results. The described method is implemented in the form of a computer program and will be used for further research.
The issues of mining the reserves of the lower horizons of the Salt-Iletsk rock salt deposit by dissolution through the wells from the surface are considered. The specifics of rock salt extraction by this method are determined by significant investments in the construction of brine field facilities and the complexity of quickly bringing the brine field to a given production capacity, which is caused, in addition to the significant cost of time for drilling and equipping wells, by the need to wash out the preparatory mine workings. Intensification of the preparatory mine opening will have the effect of reducing the payback period of capital investments, which, in turn, will affect the cost of produced brine. With the help of mathematical modeling of the process of intensification of the preparatory mine opening dissolution the following results were obtained: - optimal water consumption for dissolution of preparation workings 45-55 m3 /h (optimization criterion was electric power consumption for solvent injection); - optimal solvent temperature 180-220 °С (optimization criterion was electric power consumption for solvent injection and for water heating to the given temperature).
