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Water wells play an increasingly important role in providing water for the civilian population all over the world. Like other engineering structures, wells are subject to ageing processes resulting in degradation, which is observed as a reduction in hydraulic efficiency throughout their lifespan. To date, it has been found that the ageing process of a well is determined by a number of factors. The mathematical description of this process can be simplified. Drawing on Jacob’s equation, this paper presents the course of the degradation process as a variable depending on operation time, well loss and flow rate. To apply the determined relationships in practice, simplifying assumptions were adopted, which make it possible to determine the moment of ageing compensations of the degradation processes. It was also demonstrated that the degradation process may be slowed down by the appropriate selection of initial operating parameters. The presented discussion highlights the significance of parameters α, δ and exponent β. The relation between hydraulic resistances in an aquifer and in the engineering structure is closely connected with these values. The presented arguments indicate that step drawdown tests provide the necessary information which allows tracking changes in the ageing processes occurring in the engineering structure. The analysis of the drawdown test results makes it possible to determine the moment when the necessary adjustments in the operating parameters of a water well should be performed. Eventually, it allows maintaining the high hydraulic efficiency of the intake and extending the lifespan of the well in accordance with the principle of sustainability.
Krzysztof Polak; Kamil Górecki; Karolina Kaznowska-Opala. The Dynamics of Water Wells Efficiency Reduction and Ageing Process Compensation. Water 2019, 11, 117 .
AMA StyleKrzysztof Polak, Kamil Górecki, Karolina Kaznowska-Opala. The Dynamics of Water Wells Efficiency Reduction and Ageing Process Compensation. Water. 2019; 11 (1):117.
Chicago/Turabian StyleKrzysztof Polak; Kamil Górecki; Karolina Kaznowska-Opala. 2019. "The Dynamics of Water Wells Efficiency Reduction and Ageing Process Compensation." Water 11, no. 1: 117.
Drainage wells used in lignite mining have to be operated at high efficiency in order to achieve a targeted drawdown in the shortest time period possible. However, oversizing of pump units and excessive pumping can cause accelerated aging of wells and over time, decrease a well’s drainage efficiency. This article analyzes the case of a well that was operated for 10 years and then abandoned at a lignite mine. A common practice in installing dewatering wells in Poland is to protect the well screen with a pre-fabricated granular layer (called a “gravel coat”) that is attached to the screen when it is lowered into the hole. The combination of the gravel coat and well screen is surrounded by a protective gravel pack. Samples of the gravel coat were obtained from the abandoned well. The percentage by weight of precipitates in, and the porosity of the gravel coat from the abandoned well were determined and compared with the properties of new gravel coat material. Tests were conducted in the laboratory to compare hydraulic losses, apparent seepage velocity, effective velocity, and the hydraulic efficiency of the well’s gravel coat. The results of the tests explain the low hydraulic efficiency of the abandoned well and the origin of the damage to the gravel coat. The actual yield was also compared with the calculated theoretical safe yield, which was estimated based on the results of geological records from the construction of the well. Entwässerungsbrunnen werden im Braunkohlenbergbau verwendet um mit hoher Effizienz eine gezielte Absenkung in kürzester Zeit zu erzielen. Allerdings kann eine Überdimensionierung der Pumpeneinheiten und zu hohe Förderraten zu einer beschleunigten Alterung des Brunnens im Laufe der Zeit führen. Damit verringert sich auch die Effizienz des Förderbrunnens. Dieser Artikel untersucht den einen Brunnen der über 10 Jahre betrieben wurde und dann vom Braunkohlebergwerk stillgelegt wurde. Eine gängige Praxis beim Bau von Förderbrunnen in Polen ist es fertige Filterkiesmischungen die zusammen mit dem Filtersieb in das Brunnenloch abgesenkt wird um dieses zu schützen. Es wurden Proben aus dem Filterkies des stillgelegten Brunnens entnommen. Der Masseanteil von Ablagerungen und die Porosität der Kiesschicht wurden bestimmt. Es erfolgte ein Vergleich mit den Eigenschaften von neuen, unbenutzten Filterkiesschüttungen. Die Versuche im Labor erfolgten auf die hydraulischen Verluste, die scheinbare Sickergeschwindigkeit, die effektive Geschwindigkeit und die hydraulische Effizienz der Filterkiesschüttung. Die Ergebnisse der Versuche zeigen den geringen hydraulischen Wirkungsgrad der stillgelegten Brunnen sowie die Ursache für die Schäden am Filterkies. Die tatsächliche Ausbeute wurde mit der berechneten, theoretischen sicheren Ausbeute verglichen, die auf Grundlage der Ergebnisse der geologischen Aufzeichnungen basiert. Los pozos de drenaje usadas en la minería de lignito deben operar en alta eficiencia para alcanzar una reducción determinada en el tiempo más corto posible. Sin embargo, el sobredimensionamiento de las unidades de bombeo y el excesivo bombeo puede causar un envejecimiento acelerado de los pozos y con el tiempo, decrecer su eficiencia de drenaje. Este artículo analiza el caso de un pozo que fue operado por 10 años en una mina de lignito y luego abandonado. Una práctica común cuando se instalan pozos de desagote en Polonia es proteger la cobertura del pozo con una capa granular prefabricada (llamada una “capa de grava”) que es adherida a la cobertura que ésta es bajada dentro del pozo. La combinación de la capa de grava y la cobertura del pozo es rodeada por una protección de grava. Se obtuvieron muestras de la capa de grava del pozo abandonado. Se determinó el porcentaje en peso de los precipitados y la porosidad de la capa de grava y se compararon con las propiedades de grava nueva. En el laboratorio se hicieron estudios para comparar las pérdidas hidráulicas, la velocidad de filtración aparente, velocidad efectiva y la eficiencia hidráulica de la capa de grava del pozo. Los resultados de estos estudios explican la baja eficiencia hidráulica del pozo abandonado y el origen del daño a la capa de grava. El rendimiento real fue también comparado con el rendimiento calculado, que fue estimado en base a los resultados de los datos geológicos desde la construcción del pozo. 通常,褐煤煤矿疏水井需要高效运转以便短时间内达到目标疏降水位。然而,不匹配大型泵水装置或长期过度抽水都易造成疏水井老化和疏水效率降低。本文以一个在褐煤煤矿运行十年后报废的疏水井为例开展研究。在波兰,保护疏水井滤水管的普遍措施是在滤网外套接预制颗粒层(填砾层)并一同沉入井孔,在填砾层与滤水管外围再包裹一圈保护性砾石垫。预制填砾层样品取自该废弃疏水井,计算了预制填砾层中沉淀物的重量百分比及预制填砾层孔隙率,然后与新填砾层材料进行对比。在实验室内,实验、对比了预制填砾层的水头损失、表观流速、实际流速和导水效率。实验解释了废弃疏水井效率低和填砾层破坏的原因。同时,比较了疏水井实际出水量与基于疏水井地质结构的理论计算允许疏水量的差异。
Krzysztof Polak; Karolina Kaznowska-Opala; Katarzyna Pawlecka. Causes of Decreased Discharge and Damage to a Dewatering Well’s Gravel Coat. Mine Water and the Environment 2015, 35, 120 -127.
AMA StyleKrzysztof Polak, Karolina Kaznowska-Opala, Katarzyna Pawlecka. Causes of Decreased Discharge and Damage to a Dewatering Well’s Gravel Coat. Mine Water and the Environment. 2015; 35 (2):120-127.
Chicago/Turabian StyleKrzysztof Polak; Karolina Kaznowska-Opala; Katarzyna Pawlecka. 2015. "Causes of Decreased Discharge and Damage to a Dewatering Well’s Gravel Coat." Mine Water and the Environment 35, no. 2: 120-127.
Central Europe experienced catastrophic rainfalls and flooding in 2010. This paper discusses a decommissioned shaft that was flooded by surface water, which led to displacement of shaft backfill and an inrush of large amounts of water into an underground pumping station. The weather conditions for the period preceding the inrush, the hydrogeological conditions, the quantity of water that entered the mine dewatering systems, and the underground hydraulic connections are all described. Uncontrolled inflow of water as a cause of backfill saturation and the hazard for active underground infrastructure were analysed. A need to rebuild damaged infrastructure was identified. The case study highlights the need to improve underground mine closure requirements to ensure safe conditions above ground, particularly in densely populated areas. Mitteleuropa erlebte 2010 katastrophale Regenfälle und Hochwässer. Dieser Artikel berichtet von einem stillgelegten Bergwerksschacht, der durch Oberflächenwasser geflutet wurde, was zu einer Verlagerung von Verwahrungsmaterial im Schacht und dem Eindringen großer Mengen Wasser in eine Untergrund-Pumpstation führte. Die Wetterbedingungen vor dem Wassereinbruch, die hydrogeologischen Bedingungen, die Menge des Wassers, das in das Entwässerungssystem eindrang, und die hydraulischen Verbindungen im Untergrund werden beschrieben. Der unkontrollierte Zufluss als Ursache für die Wassersättigung des Verwahrungsmaterials und die Gefährdung der im Untergrund betriebenen Infrastruktur wurden analysiert. Es wurde festgestellt, dass die beschädigte Infrastruktur erneuert werden muss. Die Fallstudie unterstreicht, dass die Anforderungen an die Schließung von untertägigen Bergwerksanlagen verbessert werden müssen, um die übertägige Sicherheit zu gewährleisten, insbesondere in dicht besiedelten Gebieten. Europa central experimentó lluvias e inundaciones catastróficas en 2010. Este trabajo discute el caso de un acceso de mina que fue inundado por agua superficial, que provocó el desplazamiento del relleno del acceso y la irrupción de grandes cantidades de agua dentro de una estación de bombeo subterránea. Se describen las condiciones del clima para el período precedente a la irrupción, las condiciones hidrogeológicas, la cantidad de agua que entró a los sistemas de desagote de la mina y las conexiones hidráulicas subterráneas. Se analizó la entrada incontrolada de agua como una causa de saturación del relleno y el riesgo para la infraestructura subterránea activa. Se concluyó en la necesidad de reconstruir la infraestructura dañada. El caso estudiado pone énfasis en la necesidad de mejorar los requerimientos de clausura de minas subterráneas para asegurar las condiciones de seguridad sobre la superficie, particularmente en áreas densamente pobladas. 2010年中欧经历了一场灾难性降雨和洪灾。废弃煤矿竖井为地表洪水淹没之后,使竖井封孔材料下沉,最终诱发大量洪水溃入井下泵房系统。分析了废弃竖井溃水前天气状况、研究区水文地质条件、矿井泵房溃水量及废弃矿井间联通状况,解释了洪水淹没是竖井封孔材料饱和并诱发井筒溃水主要原因,分析了溃水对邻近生产矿井井下基础建设的危害,指出了需要重建的井下基础设。本案例旨在说明加强矿井闭坑管理对保护地表尤其人口密集区安全的重要性。
Krzysztof Polak; Kazimierz Różkowski; Piotr Czaja. Causes and Effects of Uncontrolled Water Inrush into a Decommissioned Mine Shaft. Mine Water and the Environment 2015, 35, 128 -135.
AMA StyleKrzysztof Polak, Kazimierz Różkowski, Piotr Czaja. Causes and Effects of Uncontrolled Water Inrush into a Decommissioned Mine Shaft. Mine Water and the Environment. 2015; 35 (2):128-135.
Chicago/Turabian StyleKrzysztof Polak; Kazimierz Różkowski; Piotr Czaja. 2015. "Causes and Effects of Uncontrolled Water Inrush into a Decommissioned Mine Shaft." Mine Water and the Environment 35, no. 2: 128-135.
Drainage of the rock mass is a key component affecting the safety of mining operations and is associated with the removal of the overburden, dumping and excavation of useful minerals. The primary method of drainage in lignite coal mines are bored wells. The efficiency of drainage of rock mass depends on their accurate positioning and quality of workmanship. The paper presents the current state of knowledge concerning the distribution of the components of drawdown (1) in pumping well (Walton, 1955; Bruin & Hudson, 1961; Kruseman & de Ridder, 1991; Avci, 1992; Atkinson, 1994; Helweg, 1994; Kawecki, 1995; Singh, 2002; Dufresne, 2011) and their dependence on the hydrogeological parameters of the drained aquifer (Fig. 2). The results of pumping tests conducted in drainage wells operating in lignite mines are also presented. The subject of analysis was the geohydraulic resistance coefficient B, describing the resistance of the aquifer under laminar flow. This coefficient also takes the hydrogeological parameters into account which determines the dynamics and range of influence of drainage (12, 13). The value of the parameter and its spatial variability can be used for planning, designing and evaluating the effectiveness of wells drainage In view of the results of the pumping tests, classification of aquifer susceptibility to drainage was proposed, which can be used to support decision-making in the scope of expansion of the drainage system, the necessary timing and dynamics of pumping water. The classification is preliminary and is the starting point for the development of methods to rationalize functioning costs of the drainage systems.
Krzysztof Polak; Karolina Kaznowska-Opala; Katarzyna Pawlecka; Kazimierz Różkowski; Jerzy Klich. The Assessment of Susceptibility on Drainage in an Aquifer on the Basis of Pumping Tests in a Lignite Mine / Ocena Podatności Ośrodka Wodonośnego Na Odwodnienie Na Podstawie Próbnych Pompowań W Kopalni Węgla Brunatnego. Archives of Mining Sciences 2015, 60, 107 -121.
AMA StyleKrzysztof Polak, Karolina Kaznowska-Opala, Katarzyna Pawlecka, Kazimierz Różkowski, Jerzy Klich. The Assessment of Susceptibility on Drainage in an Aquifer on the Basis of Pumping Tests in a Lignite Mine / Ocena Podatności Ośrodka Wodonośnego Na Odwodnienie Na Podstawie Próbnych Pompowań W Kopalni Węgla Brunatnego. Archives of Mining Sciences. 2015; 60 (1):107-121.
Chicago/Turabian StyleKrzysztof Polak; Karolina Kaznowska-Opala; Katarzyna Pawlecka; Kazimierz Różkowski; Jerzy Klich. 2015. "The Assessment of Susceptibility on Drainage in an Aquifer on the Basis of Pumping Tests in a Lignite Mine / Ocena Podatności Ośrodka Wodonośnego Na Odwodnienie Na Podstawie Próbnych Pompowań W Kopalni Węgla Brunatnego." Archives of Mining Sciences 60, no. 1: 107-121.
Krzysztof Polak; Karolina Kaznowska. Comparison of methods used in Poland for the evaluation of dewatering wells. Mine Safety and Efficient Exploitation Facing Challenges of the 21st Century 2010, 355 -360.
AMA StyleKrzysztof Polak, Karolina Kaznowska. Comparison of methods used in Poland for the evaluation of dewatering wells. Mine Safety and Efficient Exploitation Facing Challenges of the 21st Century. 2010; ():355-360.
Chicago/Turabian StyleKrzysztof Polak; Karolina Kaznowska. 2010. "Comparison of methods used in Poland for the evaluation of dewatering wells." Mine Safety and Efficient Exploitation Facing Challenges of the 21st Century , no. : 355-360.