Justification and selection of the optimal method for draining the field of the “Angrensky” open pit mine in Uzbekistan

An increase in the stability of the slopes of the sides of a quarry or a ledge when using drainage wells with a camouflage cavity is proved in the article by the polarization-optical method. On the obtained diagrams, the distribution of stresses within the massif clearly shows that in an intact massif, the main concentration of stresses is concentrated in the lower edge of the slope, which contributes to the formation of a plane of displacement of the massif and the development of deformations. The presence of a camouflage cavity leads to a redistribution of stresses with the formation of a stress concentration around the camouflage cavity and a significant decrease in the stress concentration in the lower edge of the slope. Thus, we can say that the use of wells with a camouflage cavity not only drains the rocks along the side, but also unloads the border massif, creating favorable conditions for increasing the stability of the drained slope of the side of the open pit.

Numerical Study of the Process of Unsteady Filtration of a Fluid in Interacting Porous Pressure Layers

A review of the fundamental studies conducted in 2010 - 2020 is given in the article to develop a mathematical model related to the fluid and gas filtration processes in porous media. To conduct a comprehensive study of the process of unsteady filtration of fluid in multi-layer porous pressure media and to make a management decision, a mathematical model described by a system of partial differential equations with corresponding initial and boundary conditions and a conservative numerical algorithm were developed. On the basis of the developed software of the problem posed, computational experiments were conducted on a computer; the calculation results were presented in the form of tables and graphical objects. The schemes of location and capacity of vertical drainage wells to protect irrigated and non-irrigated areas from flooding were proposed on the basis of the developed software. Using the proposed mathematical tool, it is possible to obtain the prognostic groundwater levels for any area for the required period of time, considering a number of factors, for example, the formation heterogeneity in plan, the gradient of the permeability barrier, and other hydrogeological, hydro-technical, and natural conditions; to calculate the capacity and optimal drilling pattern of vertical drainage wells to protect the territory and to develop oil and gas fields.

Irrigation of the cultivated area with groundwater from vertical drainage wells

In recent years, there has been a shortage of water resources in the basins of the Amu Darya and Syrdarya rivers, which is the result of the development of new lands for irrigation and the inappropriate use of water and land resources. A side effect of irrigation and land reclamation is the increasing flow of collector-drainage waters every year, which leads to a deterioration in the land reclamation state and pollution of water resources, which can lead to the ecological disaster of land and water resources. Currently, in the Republic of Uzbekistan, from the total volume of water resources of the Amu Darya and Syrdarya rivers, up to 68% is used for irrigation. Of this volume on the Republic territory, about 12% of collector-drainage waters of deteriorated quality are formed. With a shortage of water resources, they are used for irrigation. But irrigation with saline waters can lead to a deterioration in the land reclamation state. In this regard, new irrigation technologies are proposed, which can save both irrigation water and it is advisable to use underground pumped water for irrigation. Field experiments were carried out in the farm "Khozhilkhon-hozhi" in the farm named after A. Niyazov, Kuva district, Fergana region. A feature of the soil conditions in this farm is the small thickness of the covered fine earth, underlain by highly permeable gravel, strong and increased water permeability, with a deep groundwater level (GWL> 3 m). Large water losses are observed during irrigation. The calculation task was to determine how many hectares of land can be irrigated from one vertical drainage well, taking into account the irrigation time, inter-irrigation period, etc. The water-salt balance of the reclaimed lands for 2017-2019 was compiled. The water-salt balance showed that water supply and filtration from canals and atmospheric precipitation play the main role in the inlet part. In the consumable part, the main place is occupied by evapotranspiration and drainage flow. In general, a negative balance is formed on the territory annually by the type of a small salt carryover within 2.85 t / ha. On the territory of the farm and the experimental plot, cotton of the S-6524 variety was sown, the flow rate of the well is 30 l / s, the furrow consumption is 0.5 l / s. The composition of hypothetical salts in the pumped-out waters is calculated After the first irrigation of our field, the pumped-out water is diverted to the neighboring fields, while the first inter-irrigation period is 20 days. In the interval of these 20 days until the second irrigation of the cotton of the original field, it is possible to irrigate the same fields 5 hectares 8 times, in total 40 hectares of land. The experiments showed that irrigation with pumped water from vertical drainage wells did not have a negative impact on the yield of cotton. And the use of the recommended irrigation technology will reduce the shortage of irrigation water and improve the ecological situation of water resources.

Construction of vertical drainage wells using corrosion resistant materials

Vertical drainage wells in terms of construction technology and design do not differ from wells for irrigation. They are not deeper in-depth than irrigation wells and are generally 40-70 m. The main task of vertical drainage wells is land reclamation. They, depending on natural and economic conditions, serve on 5-120 hectares of area. In many areas, vertical drainage wells serve a dual purpose; land reclamation and irrigation of agricultural crops. Water intake wells, including vertical drainage wells, are characterized by a decrease in their flow rates during operation. To ensure the stable operation of the irrigation and drainage system, where water intake wells are operated, repair and restoration work is carried out on them, aimed at increasing flow rates. For the construction of vertical drainage wells in the Sirdarya river basin, steel pipes and filters are mainly used, which corrode in an aggressive environment. In the water intake zone of the well and the metal corrosion process, the colmatation process also occurs. All of them are the main reasons for the decline in well production rates. The carried out repair and restoration measures are aimed at destroying the structure of corrosion and clogging products. In practice, mechanical, physical, biological, and chemical methods are used to clean the filters of water intake wells. They all have their own technology and equipment. However, all these works do not exclude the repeatability of the process. Repetitive workover will come to ineffective, the stage of good concertation is approaching. It is known that polymeric materials do not corrode. They work steadily in aggressive environments. To prevent the corrosion process, polymeric-seam pipes were used as a filter frame and a casing for the construction of vertical drainage wells. Two pilot wells were built on the territory of the Chiyili district of the Kyzylorda region of the Republic of Kazakhstan. The wells were drilled with a rotary drilling unit with backwash. Pure water (irrigation) was used as drilling fluid. To form a gravel pack in the annular zone of the casing, gravel-sand material from the Jailma quarry was used. The material was brought by rail and road transport. Pipe sections were prepared on the surface of 10 meters. Steel rings were put on the pipe from both ends of each section; their connection in the barrel was made by electric welding. The results showed that in the initial period of operation, a decline process was observed. In further exploitation, the well flow rate stabilized. As a result of construction using pipes and filters made of polymer material, the effect was achieved in terms of water volume more than 3 times and in terms of service life 4.2 times compared to a metal filter well.

Numerical study of fluid filtration in three-layer interacting pressure porous formations

A mathematical model was developed to numerically study the process of fluid and gas filtration in three-layer interacting pressure porous formations. It is based on the reviews related to the mathematical modeling developed in recent years; it describes a system of partial differential equations with boundary and initial conditions and a conservative numerical algorithm for conducting a computational experiment (CE) on a computer. In this article, to analyze and make managerial decisions, the results of numerical calculations are presented in the form of graphical objects, which can be used to propose schemes for the location and capacity of vertical drainage wells to protect irrigated and non-irrigated areas from flooding. Using the proposed mathematical tool, it is possible to obtain the predicted groundwater levels of any area for the required period of time, taking into account some factors, such as the inhomogeneity of the reservoir in a plan, the slope of the confining layer, and other hydrogeological, hydro-technical, and natural conditions, or to calculate the thickness and the optimal location of vertical drainage wells to protect the territory, and to develop oil and gas fields and increase their oil and gas recovery. Analysis of the results of a numerical study of the process made it possible to establish the degrees of influence of the elastic filtration regime in a weakly permeable layer on the overflow into adjacent layers.

OPERATION MODE OF VERTICAL DRAINAGE WELLS DURING IRRIGATION AND NONIRRIGATION PERIODS

В статье изложены результаты полевых исследований по разработке режима работы скважин вертикального дренажа при возделывания хлопчатника в оросительный и вневегетационный периоды в условиях Мактааральского массива Туркестанской области. Известно, что по характеру участия грунтовых вод в процессах почвообразования в природных условиях выделяются два основных типа режимов почвообразовательного процесса - гидроморфный и автоморфный и два промежуточных - полугидроморфный и полуавтоморфный. Принято различать и соответствующие им мелиоративные режимы. Вертикальный дренаж в отличие от других видов дренажа позволяет поддерживать (и создавать) полугидроморфный режим, что особенно важно для вновь орошаемых земель с исходно глубоким уровнем грунтовых вод, где необходимо сохранить этот уровень, не допустить его подъема и предотвратить тем самым продвижение солей к зоне аэрации, необходимой для выращивания растений. Установлено, что обеспечения благоприятного мелиоративного состояния орошаемых земель скважины вертикального дренажа в оросительный период (май-август) должны работать на нормальную нагрузку с коэффициентом полезной работы (КПР) в пределах 0,3-0,35, вневегетационный период (сентябрь-октябрь) с КПР равным 0,35-0,50. Ключевые слова: режим работы, вертикальный дренаж, орошаемые земли, мелиоративный режим, грунтовая вода, зона увлажнения

IRRIGATION BY GROUNDWATER AT THE EXPERIMENTAL AREA IN THE KUVINSKY DISTRICT OF THE FERGANA REGION

The article talks about the rational use of water pumped out of vertical drainage wells. The solution to the problem is determined by irrigation with water from vertical drainage wells, without dumping them into the collector-drainage network. An example of irrigation is given on the experimental plot of the Kuva region, the farm "Musazhon Ismoilov".

INFLUENCE OF DRAINAGE WELLS IN ANTIFILTRATION DRAINAGE SYSTEM

The decrease of water levels in the drainage wells of the coastal anti-filtration drainage system with the siphon method of water intake from them was analyzed. The interaction of water-lowering wells with different depths and located at variable distances from each other is considered, which makes it possible to ensure uniform drainage from each well and to achieve a steady decrease in the level of groundwater over the entire length of the antifiltration drainage system.The results of the performed analytical studies are presented. The example of the Kamyanka-Dniprovska's anti-filtration drainage system shows that the decrease in water levels in wells at the same flow rate of pumped water depends on their hydraulic interaction, hydrogeological conditions of water filtration from the aquifer and the distance of the antifiltration drainage system from the bank-side. The results obtained indicate that the highest level of water depletion of the coastal vertical anti-filtration drainage system line with siphon drainage from wells is achieved at a distance of a number of wells from the Kakhovsky reservoir bank-side a = 100 m, at the same water flow rate from each of the drainage wells (Q = 604,8 m3 /day), located at different distances from each other. The highest rate of additional reduction of water obtained through mutual hydraulic action was obtained in the 7th well, which has a depth of 14,9 m, and it is located at a distance of 100 m from the 6th well and at a distance of 110 m from the 8th well. The lowest indicator of the level of groundwater reductions at different indicators of the distance of a number of drainage wells to the bank-side a (30, 50, 80, 100 m) is observed in the first well, farthest from the water collection well.