Liquid loading in gas wells leads to production challenges and decreases the overall recovery from these wells. Gas wells affected by liquid loading struggle to eliminate the liquid that accompanies the produced gas from the wellbore. The primary cause of liquid loading is a low gas flow rate or gas velocity. When the gas velocity falls below the critical threshold needed to transport liquid to the surface, the liquid begins to accumulate in the vertical section of a well, the lateral section of a horizontal well, and even within hydraulic fractures. Another indication of liquid loading is the high casing over tubing pressure. The focus of the case study on an onshore gas well is addressing the issue of liquid loading in Southern Pannonian Basin conditions. A well was selected that experienced a gradual decline in production and head pressure. A model was created using PipeSim software, followed by a sensitivity analysis under various operational scenarios. The significance of this study lies in optimizing the well parameters to prevent the occurrence of liquid loading. The paper is structured around relevant works, background, case study, methodology, results, and conclusions.

This paper analyses the planning of operation for underground mining trucks powered by Lithium-ion batteries. Trucks supplied by the companies Epiroc and Sandvik are used as examples, comparing their characteristics with equivalent diesel-engine models. These trucks have similar payload capacities and dimensions, but significant differences in available energy, demonstrating that battery-powered trucks have substantially lower autonomy. The paper describes a method for estimating the autonomy of battery-powered trucks, considering motor efficiency, energy losses, and regenerative braking. A procedure is presented for determining the energy consumption for truck movement along a known route, considering the total resistance. It is demonstrated that the lower available energy of battery-powered trucks is a major factor necessitating a different approach to planning their operation in underground mining.

A best-suited method for rock excavation at the hilltop has been identified in the present paper for construction of a Ground Level Service Reservoir (GLSR) in a densely populated urban area. At the foothill, several residential houses are located at 70 meters from the excavation boundary. Due to presence of hard granitic rock, the previously adopted method using a non-explosive silent cracking agent combined with hydraulic rock breakers and excavators became inefficient in achieving the required production targets. Hence, various alternative rock excavation methods were evaluated considering two key factors, timely completion and safety of nearby structures. Various rock-breaking techniques such as hydraulic rock breakers, static expansion agents, plasma blasting and heat-assisted splitting were reviewed thoroughly, but they found to be time-consuming and inadequate for completing the project within the time schedule. The use of explosives and controlled blasting method emerged as the only viable option provided the emanating ground vibrations, noise, and flyrock are maintained within permissible limits. Based on data from different sites with similar geological conditions, a vibration prediction equation was developed and accordingly, appropriate controlled blasting patterns along with an optimized excavation methodology were proposed to ensure safe rock excavation within the designated timeframe.

Small-diameter drilling is used in many civil and mining engineering applications. In the past, it was mainly performed with hand-held hammer drills. However, the need for safer and more efficient work has led to the development of small self-propelled drilling machines that require fewer workers to achieve the same output while providing significantly safer working conditions. Small-diameter boreholes are used in specialized blasting methods (e.g., blasting in urban areas, secondary Boulder blasting), during the extraction of decorative stone blocks, for installing anchors in slope stabilization, in underground mining, in the application of expansive mortar for the disintegration of solid masses (stone, concrete), for creating protective screens, tunneling, and more. Several manufacturers produce small self-propelled drill rigs, all equipped with remote controls. This eliminates the need for the operator to stand in potentially hazardous positions, as is required when using hand-held hammer drills. This paper presents the capabilities and application methods of these drill machines under various working conditions.

Longwall top coal caving (LTCC) is a mining technology introduced for enhancing the coal production rate by using the top coal caving (TCC) operations for thick seams. LTCC mine increases coal production rates but at the expense of high dust exposure and may create hazardous conditions for mine operators. It is vital for the introduction of advanced dust control technologies as well as strategies during LTCC operations for dust reduction. For developing LTCC dust control strategies, fundamental understanding of transient caving dust flow pattern across the face is necessary. Note, region above the rear armored face conveyor (AFC) is difficult to access for carrying out field measurements and hence numerical approach is the only option left for determining the dust and flow fields. In this paper, an attempt is made to predict respirable dust flow patterns during sequential caving operations in the mid face region using computational fluid dynamics (CFD) techniques. Results predicted caving dust sources entering the downstream chock and dispersing into the walkway region within 5 seconds. Respirable dust in the first downstream walkway remains below 2mg/m³ whereas in the second downstream chock in the sequence is above 2.5mg/m³. Interpreting the results, it can be inferred that caving dust controls using water sprays need to be activated in not only in the caving chock but also in the immediate downstream chock from the start of the sequence caving for preventing the migration respirable dust into the walkway regions of the downstream chocks until the completion of the sequential caving operation in all the five chocks.

Chemical reactions in the solid phase are characterized by many specificities. The study of such reactions, with regard to the condensed state, eliminates the need to introduce many approximations that are common when considering reactions in the liquid phase or heterogeneous reactions, other laws, specific and inherent only to the solid state of matter. These make the scientific field of solid-state chemistry far more complex, due to the very strong need for a comprehensive multidisciplinary approach. The basic theoretical principles from the fields of physics, chemistry, physical chemistry and chemical technology are equally important. The article gives an example of mechanochemical synthesis of the neutralization type, and barium oxide as the base component and titanium oxide as the sisal component of the mixture are activated. In order to determine the changes that occur due to the mechanical activation of the starting materials, barium oxide and titanium oxide were ground in a stoichiometric ratio for 440 minutes. The analysis determined that a mechanochemical synthesis had taken place and that barium titanate with a degree of synthesis of 0.99 had been obtained. This was confirmed using X-ray structural analysis, which monitored the state of the activated material as a function of the time of activation.

This paper explores the optimization of oil production by using sucker rod pumps while maintaining optimal system balance. Loss of efficiency due to unbalanced pump units and increased energy requirements are the key challenges in the exploitation of oil wells. In order to overcome these problems, an intelligent monitoring system has been explored and it integrates sensors, SCADA platform and predictive algorithms for real-time performance monitoring. The research has been conducted on five oil wells, where the key parameters, electric current, motor power and gearbox torque have been analyzed - before and after balancing the system. The results show a reduction in peak current and motor power, as well as the elimination of negative torque, thus increasing the efficiency and reliability of the equipment. Based on the calculation of electricity consumption, savings of 8% to 14% have been recorded, with an average value of 11%. In addition to energy efficiency, optimal balancing contributes to extending the service life of the gearbox and reducing the number of production downtime. The obtained results confirm that the combination of CBM approach and intelligent remote monitoring is a reliable basis for improving the exploitation of oil by using sucker rod pumps. This approach contributes to reducing operating costs, preserving equipment and achieving sustainable development goals in the oil industry.

In this paper the investigation results of adsorption of uranyl ion on unmodified and acid modified clinoptilolite are presented. Adsorption was investigated at different amounts of adsorbents in suspension, different concentrations of uranyl ion in solution, as well as at different pH values.

The pre-concentration of Pb-Zn ores is commonly performed using gravity concentration in a dense medium. The primary objective of this process is to remove coarse-grained gangue from fully crushed ore using a cost-effective method, while keeping the loss of valuable metals within acceptable limits-comparable to or lower than those observed in flotation processes. Laboratory tests on ore from the Lece deposit indicate that gravity concentration in a dense medium can successfully remove over 60% of coarse-grained gangue from fully crushed ore. From a process applicability standpoint, this represents a promising result. However, the associated losses of valuable metals-particularly gold and silver-are substantial, reaching approximately 50%. Gold is the most valuable component in the Lece ore. Therefore, pre-concentration at the final crushing stage is not considered feasible at industrial scale.

The influence of pH on the corrosion behavior of X12CrMoWVNbN10-1-1 steel was examined in 0.1 M NaCl solution. The rate of general (uniform) corrosion of the tested steel was determined using linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) methods. In the NaCl solution with a pH of 2.9, the tested steel exhibited a more negative corrosion potential and lower corrosion resistance. Significantly higher corrosion potential and resistance to general corrosion were observed in a neutral solution (pH = 6.5), where the steel was in a passive state.