-
Date submitted2021-12-16
-
Date accepted2022-04-07
-
Date published2022-07-13
The Upper Kotlin clays of the Saint Petersburg region as a foundation and medium for unique facilities: an engineering-geological and geotechnical analysis
- Authors:
- Regina E. Dashko
- Georgiy A. Lokhmatikov
The article reviews the issues concerned with correctness of the engineering-geological and hydrogeological assessment of the Upper Kotlin clays, which serve as the foundation or host medium for facilities of various applications. It is claimed that the Upper Kotlin clays should be regarded as a fissured-block medium and, consequently, their assessment as an absolutely impermeablestratum should be totally excluded. Presence of a high-pressure Vendian aquifer in the lower part of the geological profile of the Vendian sediments causes inflow of these saline waters through the fissured clay strata, which promotes upheaval of tunnels as well as corrosion of their lining. The nature of the corrosion processes is defined not only by the chemical composition and physical and chemical features of these waters, but also by the biochemical factor, i.e. the availability of a rich microbial community. For the first time ever, the effect of saline water inflow into the Vendian complex on negative transformation of the clay blocks was studied. Experimental results revealed a decrease in the clay shear resistance caused by transformation of the structural bonds and microbial activity with the clay’s physical state being unchanged. Typification of the Upper Kotlin clay section has been performed for the region of Saint Petersburg in terms of the complexity of surface and underground building conditions. Fissuring of the bedclays, the possibility of confined groundwater inflow through the fissured strata and the consequent reduction of the block strength as well as the active corrosion of underground load-bearing structures must be taken into account in designing unique and typical surface and underground facilities and have to be incorporated into the normative documents.
-
Date submitted2020-06-19
-
Date accepted2020-10-06
-
Date published2020-11-24
Practice of using the magnetic treatment devices to intensify the processes of primary oil treating
During the primary treatment of oil, gas and water, complications arise associated with the presence of hard water-oil emulsions, which cause an increase in fluid pressure in the gathering systems, pipeline damage, as well as difficulties in gas separation and preliminary water discharge at the preliminary discharge unit (PRU). Additional problems arise during transportation of highly paraffinic oils associated with the crystallization of paraffin in the flow path of the oilfield equipment and on the inner surface of pipes, leading to a drop in the productivity of pipelines. Article discusses the technology of magnetic-reagent treatment of water-oil media, which allows intensifying the processes of primary oil treatment at the facilities of its production. Bench and pilot tests have shown the ability of the magnetic field to accelerate oil demulsification processes, increasing the percentage of separated water during subsequent settling, and to reduce asphalt-resin-paraffin deposits (ARPD) on the inner surface of oil and gas field equipment. Mechanism of the magnetic field effect on water-oil media is described. Effect of treatment on the integrity of the armour shells of oil-water emulsions was studied. Various modes of magnetic treatment have been investigated with evaluation of its effectiveness. It is shown that the best effect is achieved with the combined use of reagents and a magnetic field. Synergistic effect is observed, which consists in increasing their effectiveness. This made it possible to conclude that this method can be applied to reduce the consumption of reagents used in oil production while maintaining the treatment efficiency.
-
Date submitted2019-05-26
-
Date accepted2019-07-23
-
Date published2019-10-23
Ensuring Stability of Undermining Inclined Drainage Holes During Intensive Development of Multiple Gas-Bearing Coal Layers
At high rates of production face advance, requirements towards reliable operation of undermining drainage holes get raised. The issue of maintaining high intensity of gaseous seams development under naturally increasing gas content, mining depth and capacity of production equipment poses a problem. The greatest threat comes from the loss of hole stability in the bearing pressure affected zone (in front of the face) and in the intensive shift area of overhanging rock corbels (behind the face). Intensification of air leaks due to deformation of borehole channel leads to impoverishment of removed methane-air mixture and an increasing risk to disturb safe aerogas regime in the mining area. The paper describes a mechanism of how coal-face operations affect the state of underground holes and formation of overhanging rock corbels. A typification of basic kinds of borehole deformations is presented. Authors point out critical disadvantages of the most widely-used technological schemes of gaseous seams development under high load on the production face, which hinder normal operation of a gas drainage system. As a result of research, a dependency of shot hole number, as well as the distance between shot hole axes and the borehole, on the stress state of the borehole outline has been defined more precisely. Basing on that, a formula to calculate drilling parameters of the discharge hole system has been suggested. Implementation of these measures will allow to increase the efficiency of underground gas drainage and to maintain growing intensity of gaseous coal seam development.
-
Date submitted2019-03-25
-
Date accepted2019-05-14
-
Date published2019-08-23
Increase in Intake Capacity by Dynamic Operation of Injection Wells
- Authors:
- E. V. Belonogov
- A. Yu. Korovin
- A. A. Yakovlev
The method of pumping water to compensate for fluid withdrawals from an oil formation in order to maintain formation pressure has long established itself as an effective technology and is widely used at oil and gas fields. At the same time, field operator is often faced with the problem of reduction in the intake capacity of injection wells, which may be caused by various complications arising in the near-wellbore area due to a violation of water treatment technology or other factors. This problem is typical for reservoirs with low permeability values, which leads to a decrease in the performance indicators of the formation pressure maintenance system. In order to counter contamination of the bottomhole zone of the well, as a rule, injection of specialized acid compositions for the purpose of cleaning is used. To increase the effectiveness of this procedure, the authors of the article propose to discharge the injection well at the maximum permissible speeds. This event will allow primary cleaning of the bottomhole zone of the formation from moving particles clogging the pore space, and reduce formation pressure in the vicinity of the injection well, which will subsequently improve the intake capacity of the well during treatment with acid compositions. The decrease in formation pressure in the bottomhole zone of the well also has a positive effect on the radius of acid penetration into the formation. The proposed approach has been successfully tested on a number of injection wells at one of «Gazprom Neft» enterprises. The results of pilot operations showed an increase in the quality of cleaning the bottomhole zone of the formation and an increase in the intake capacity of injection wells with subsequent preservation of intake dynamics.
-
Date submitted2018-01-15
-
Date accepted2018-02-28
-
Date published2018-06-22
About the role of hydrafed calcium carboaluminates in improving the technology of complex processing of nephelines
- Authors:
- V. M. Sizyakov
- V. N. Brichkin
The scientific justification and development of the method for industrial synthesis of complex aluminates of alkaline earth metals is an innovative solution that determined several directions in the development of technology for complex processing of nepheline raw materials. It ensures the production of high-quality metallurgical alumina, the effective utilization of nepheline sludge and production of new types of multipurpose by-products. The modern development of these technical solutions is associated with ensuring the energy efficiency of the synthesis of hydrafed calcium carboaluminates (HCCA) and increasing the level of purification of aluminate solutions. The conditions for synthesizing HCCA with the use of calcareous materials of natural and technogenic origin have been experimentally determined, which makes it possible to isolate the average particle diameter as one of the determining factors of this process. The effect of the turnover of the hydrogarnet sludge on the removal of kinetic limitations in the process of deep desalination of aluminous solutions is theoretically justified. The conditions of a two-stage dosage of HCCA are experimentally determined. It is shown that the optimum ratio of the amount of the reagent supplied in the first and second stages is about 3: 2. At the same time, the maximum degree of precipitation of silica provides the production of aluminate solutions with a silicon module at the level of 95,000, which is achieved by using a HCCA synthesized based on chemically precipitated calcium carbonate in the processing of wastes from the production of mineral fertilizers.
-
Date submitted2014-11-07
-
Date accepted2015-01-07
-
Date published2015-10-26
The concept of reducing the risks of potash mines flooding caused by groundwater inrush into excavations
- Authors:
- V. P. Zubov
- A. D. Smychnik
Results of the analysis of factors influencing the probability of accidental groundwater inrush into mine workings of salt (potash, potassium and magnesium) mines are given in the article. The cases of the potash mine flooding that occurred in different countries with developed mining industry are given. It is shown that at the present technical and scientific level of solving this problem the unexpected groundwater inrush in potash mines usually results in the shutdown of the enterprise and negative ecological consequences. It is pointed out that the underground waters flow into the mines through water-conducting fractures of either natural or technogenic origin which location and influence on a mine was almost impossible to predict at the design stage under existing regulations. The concept of reducing the risks of potash mine flooding caused by underground waters in-rush is formulated. Administrative and technical measures which allow reducing the risks of potash mine flooding caused by groundwater inrush into the excavations are considered.
-
Date submitted2009-08-13
-
Date accepted2009-10-30
-
Date published2010-02-01
Reducing losses ore between whole chamber for the design of lower layers mine by Gubkin of open joint-stock company «Industrial complex KMAruda»
- Authors:
- E. I. Boguslavskiy
- P. V. Korzhavykh
Technological decisions on decrease in losses of ore in between chamber walls are considered at designing of the bottom horizons of mine of Gubkin. It is offered two variants of decrease in losses of the ore technologically compatible with each other for their simultaneous use. Results of calculation of losses of ore and economic consequences are resulted. The basic actions which are necessary for carrying out, before introduction of technological decisions in manufacture are described.
-
Date submitted2008-11-08
-
Date accepted2009-01-26
-
Date published2009-12-11
Principles optimization of expenses for the labour protection of the mining enterprises
Classification of damage from accidents and crashes is given. Procedure optimization expenses for a labour protection and definition of economically sound risk of accidents and crashes is offered. The estimation of economic efficiency of personnel development serving the self-propelled mining equipments on ore mine «Northern» of industrial complex «Pechenga Nikel» is carried out.