scholarly journals Design and Implementation of a Coalbed Methane Extraction Device Using Microwave Radiation

2021 ◽  
Author(s):  
Ali Jebelli ◽  
Arezoo Mahabadi ◽  
Rafiq Ahmad
Keyword(s):  
Coal Mining ◽  
Microwave Radiation ◽  
Coalbed Methane ◽  
Global Economy ◽  
Coal Mines ◽  
Clean Energy ◽  
Potential Hazard ◽  
Coal Seams ◽  
Continuous Growth ◽  
Methane Gas

Abstract The continuous growth of the population and the global economy increases the need for sustainable energy. To this end, the recovery factor of hydrocarbon resources in the world should be maximized. One of the main sources of natural gas is coalbed methane, a gas accumulated in pores inside coal. On the other hand, methane gas explosion is a potential hazard in coal mines, which causes many casualties every year in coal mines worldwide. Mine ventilation alone cannot create a safe environment for coal mining due to the high volume of gas released in some coal seams. Therefore, Methane gas extraction can turn one of the major hazards in coal mining into a clean energy source and have dual benefits. Unfortunately, the permeability of most coal seams is very low, and this low permeability limits the development and production of commercial coalbed methane. Therefore, coalbed methane reservoir stimulation is an attractive option because the relative permeability of natural fractures in the coal seam and the surrounding rock greatly affects the amount of extractable gas. Microwave radiation is one of the new methods to increase the permeability of coal. In this research, we design, simulate and implement a small, lightweight, portable microwave gun that uses a conical horn with an aperture of 28 cm with a working frequency of 2.45 GHz to evaporate the moisture in the circle with a diameter of 40 cm from a coal wall and increases the permeability of the wall due to microwave radiation. Because in previous studies, the tests were performed only on large and small capacity devices without any control over the amount of microwave radiation and by replacing the gas inside the chamber with argon or nitrogen gases, which does not represent the real conditions in the mines. Therefore, by building a small device, we have overcome the limit of coal size and amount. By considering the coal ignition temperature, we have provided the challenges related to removing oxygen from the air and the possibility of working in real conditions in mines with larger volumes of coal, which is very similar to the mining environment. Also, the proposed small and portable device in this paper allows us to use it in different environments.

scholarly journals Methane Content Estimation in DuongHuy Coal Mine

2018 ◽  
Vol 35 ◽  
pp. 01005 ◽  
Author(s):  
Van Thinh Nguyen ◽  
Waldemar Mijał ◽  
Vu Chi Dang ◽  
Thi Tuyet Mai Nguyen
Keyword(s):  
Experimental Data ◽  
Coal Mining ◽  
Coal Mine ◽  
Coal Mines ◽  
Methane Content ◽  
Underground Coal Mining ◽  
Coal Seams ◽  
Underground Coal Mine ◽  
Different Depths ◽  
Quang Ninh

Methane hazard has always been considered for underground coal mining as it can lead to methane explosion. In Quang Ninh province, several coal mines such as Mạo Khe coal mine, Khe Cham coal mine, especially Duong Huy mine that have high methane content. Experimental data to examine contents of methane bearing coal seams at different depths are not similar in Duong coal mine. In order to ensure safety, this report has been undertaken to determine a pattern of changing methane contents of coal seams at different exploitation depths in Duong Huy underground coal mine.

Coalbed methane extraction and utilization

2003 ◽  
Vol 217 (1) ◽  
pp. 19-25 ◽  
Author(s):  
D Creedy ◽  
H Tilley
Keyword(s):  
Coalbed Methane ◽  
Coal Mines ◽  
Energy Resource ◽  
Industrial Processes ◽  
Biological Processes ◽  
Coal Seams ◽  
Abandoned Coal Mines ◽  
Coal Technology ◽  
Combustible Gases ◽  
Technology Programme

Coalbed methane (CBM) is the generic name for all methane of coal seam origin. It is a natural gas formed by geological, or biological, processes in coal seams and generally consists predominantly of methane, but may also contain some higher alkanes and non-combustible gases. Methane is released whenever coal is de-stressed or fractured by mining. Methane is one of the main greenhouse gases contributing to global warming, therefore releasing it to atmosphere is an environmental hazard. However, it is also an important energy resource and can be recovered from operational coal mines, abandoned coal mines, and virgin (unmined) coal seams. Significant volumes of CBM are exploited worldwide for space heating, industrial processes, and power generation. This paper critically reviews the current UK and worldwide status of CBM extraction and utilization technologies building on a previous study funded through the Department of Trade and Industry's Cleaner Coal Technology Programme [1].

scholarly journals Allocation of the geo-dynamically hazardous zones during intensive mining of flat-lying coal seams in the mines of SUEK-Kuzbass JSC

2019 ◽  
Vol 134 ◽  
pp. 01022
Author(s):  
Evgeny Yutiaev ◽  
Anatoly Meshkov ◽  
Anton Popov ◽  
Arcady Shabarov
Keyword(s):  
Rock Mass ◽  
Coal Mining ◽  
Coal Mines ◽  
Coal Industry ◽  
Comprehensive Approach ◽  
Underground Coal Mining ◽  
Coal Seams ◽  
Mining Operations ◽  
Technological Level ◽  
The Cost

Hazardous and ineffective mines were closed, and a number of underground and strip mines of a modern technological level were built as a result of the restructuring of the coal industry in Russia. However, safety in the coal mines continues to be one of the urgent issues nowadays. In underground coal mining, the main types of risks are processes occurring in the rock mass as a result of mining operations. It is necessary to realize timeous and the most accurate prediction of harmful events, which occur during a development of coal fields, to increase the efficiency and reduce the cost of coal mining. The most optimal and, at the same time, comprehensive approach to predicting possible natural hazardous events in the process of modern coal mining are considered in this article. The results of implementation of integration of different methods of geodynamic and geomechanics researches are presented in this paper.

scholarly journals Reserves Estimation for Coalbed Methane Reservoirs: A Review

2020 ◽  
Vol 12 (24) ◽  
pp. 10621
Author(s):  
Ali Altowilib ◽  
Ahmed AlSaihati ◽  
Hussain Alhamood ◽  
Saad Alafnan ◽  
Sulaiman Alarifi
Keyword(s):  
Coalbed Methane ◽  
Global Economy ◽  
Material Balance ◽  
Reservoir Properties ◽  
Continuous Growth ◽  
Well Completion ◽  
Well Spacing ◽  
Decline Curve ◽  
Coal Classification ◽  
Increasing Demand

A continuous growth in the global economy and population requires a sustainable energy supply. Maximizing recovery factor out of the naturally occurring hydrocarbons resources has been an active area of continuous development to meet the globally increasing demand for energy. Coalbed methane (CBM), which is one of the primary resources of natural gas, associates complex storage mechanisms and requires some advanced recovery techniques, rendering conventional reserve assessment methods insufficient. This work presents a literature review on CBM in different aspects. This includes rock characteristics such as porosity, permeability, adsorption capacity, adsorption isotherm, and coal classification. In addition, CBM reservoirs are compared to conventional reservoirs in terms of reservoir quality, reservoir properties, accumulation, and water/gas saturation and production. Different topics that contribute to the production of CBM reservoirs are also discussed. This includes production mechanisms, well spacing, well completion, and petrophysical interpretations. The main part of this work sheds a light on the available techniques to determine initial-gas-in-place in CBM reservoirs such as volumetric, decline curve, and material balance. It also presents the pros and cons of each technique. Lastly, common development and economic challenges in CBM fields are listed in addition to environmental concerns.

scholarly journals A Novel Hydraulic Mode to Promote Gas Extraction: Pressure Relief Technologies for Tectonic Regions and Fracturing Technologies for Nontectonic Regions

2019 ◽  
Vol 9 (7) ◽  
pp. 1404 ◽  
Author(s):  
Shaojie Zuo ◽  
Zhaolong Ge ◽  
Zhe Zhou ◽  
Li Wang ◽  
Hanyun Zhao
Keyword(s):  
High Efficiency ◽  
Coal Mines ◽  
Clean Energy ◽  
Extraction Time ◽  
Efficient Production ◽  
Gas Extraction ◽  
Coal Seams ◽  
Pressure Relief ◽  
Gas Concentration ◽  
Coal Roadway

Extraction of gas (coalbed methane) produces clean energy and can ensure that coal mines maintain high-efficiency production. The currently available coal seam permeability enhancing technologies and modes have certain application restrictions. Therefore, a novel mode is proposed to promote gas extraction. This mode divides complex coal seams into tectonic regions and nontectonic regions based on geological structures. Then, the characteristics of different regions are matched with the advantages of different hydraulic technologies; thus, pressure relief technologies are proposed for tectonic regions, and fracturing technologies are proposed for nontectonic regions. The permeability of coal seams will be sharply increased without leaving unfractured areas. This mode will promote the effectiveness of gas extraction, shorten the extraction time, and ensure safe and efficient production in coal mines. A field application shows that this mode has a better effect than slotted directional hydraulic fracturing technology (SDHFT). The gas concentration and pure gas flow were increased by 47.1% (up to 24.94%) and 44.6% (up to 6.13 m3/min), respectively, compared to SDHFT over 9 months. The extraction time was reduced by 4 months. This mode reduced the number of times that gas concentration exceeded government standards during coal roadway excavation, and the coal roadway excavation speed was increased by 16% (up to 158 m/month).

Working conditions and occupational pathology of coal miners in the Arctic

2019 ◽  
pp. 452-457 ◽  
Author(s):  
S. A. Gorbanev ◽  
S. A. Syurin ◽  
N. M. Frolova
Keyword(s):  
Coal Mining ◽  
Working Conditions ◽  
Occupational Diseases ◽  
Climatic Factors ◽  
Coal Mines ◽  
The Arctic ◽  
Morbidity Rate ◽  
Coal Miners ◽  
Increased Risk ◽  
The Impact

Introduction. Due to the impact of adverse working conditions and climate, workers in coal-mining enterprises in the Arctic are at increased risk of occupational diseases (OD).The aim of the study was to study the working conditions, causes, structure and prevalence of occupational diseases in miners of coal mines in the Arctic.Materials and methods. Th e data of social and hygienic monitoring “Working conditions and occupational morbidity” of the population of Vorkuta and Chukotka Autonomous District in 2007–2017 are studied.Results. It was established that in 2007–2017 years, 2,296 ODs were diagnosed for the first time in 1851 coal mines, mainly in the drifters, clearing face miners, repairmen and machinists of mining excavating machines. Most often, the ODs occurred when exposed to the severity of labor, fibrogenic aerosols and hand-arm vibration. The development of professional pathology in 98% of cases was due to design flaws of machines and mechanisms, as well as imperfections of workplaces and technological processes. Diseases of the musculoskeletal system (36.2%), respiratory organs (28.9%) and nervous system (22.5%) prevailed in the structure of professional pathology of miners of coal mines. Among the three most common nosological forms of OD were radiculopathy (32.1%), chronic bronchitis (27.7%) and mono-polyneuropathy (15.4%). In 2017, coal miners in the Arctic had a professional morbidity rate of 2.82 times higher than the national rates for coal mining.Conclusions. To preserve the health of miners of coal mining enterprises, technical measures to improve working conditions and medical interventions aimed at increasing the body’s resistance to the effects of harmful production and climatic factors are necessary.

scholarly journals Stress-Dependent Deformation and Permeability of a Fractured Coal Subject to Excavation-Related Loading Paths

2021 ◽  
Author(s):  
Wenzhuo Cao ◽  
Qinghua Lei ◽  
Wu Cai
Keyword(s):  
Coal Mining ◽  
Coalbed Methane ◽  
Axial Stress ◽  
Equilibrium Phase ◽  
Natural Fracture ◽  
Equivalent Permeability ◽  
Coal Matrix ◽  
Bedding Planes ◽  
Fractured Coal ◽  
Stress Dependent

AbstractThe deformation and permeability of coal are largely affected by the presence and distribution of natural fractures such as cleats and bedding planes with orthogonal and abutting characteristics, resulting in distinct hydromechanical responses to stress loading during coal mining processes. In this research, a two-dimensional (2D) fracture network is constructed based on a real coal cleat trace data collected from the Fukang mine area, China. Realistic multi-stage stress loading is designed to sequentially mimic an initial equilibrium phase and a mining-induced perturbation phase involving an increase of axial stress and a decrease of confining stress. The geomechanical and hydrological behaviour of the fractured coal under various stress loading conditions is modelled using a finite element model, which can simulate the deformation of coal matrix, the shearing and dilatancy of coal cleats, the variation of cleat aperture induced by combined effects of closure/opening, and shear and tensile-induced damage. The influence of different excavation stress paths and directions of mining is further investigated. The simulation results illustrate correlated variations among the shear-induced cleat dilation, damage in coal matrix, and equivalent permeability of the fractured coal. Model results are compared with results of previous work based on conventional approaches in which natural fracture networks are not explicitly represented. In particular, the numerical model reproduces the evolution of equivalent permeability under the competing influence of the effective stress perpendicular to cleats and shear-induced cleat dilation and associated damage. Model results also indicate that coal mining at low stress rates is conducive to the stability of surrounding coal seams, and that coal mining in parallel to cleat directions is desirable. The research findings of this paper have important implications for efficient and safe exploitation of coal and coalbed methane resources.

scholarly journals Environmental Risk Related to the Exploration and Exploitation of Coalbed Methane

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6537
Author(s):  
Barbara Uliasz-Misiak ◽  
Jacek Misiak ◽  
Joanna Lewandowska-Śmierzchalska ◽  
Rafał Matuła
Keyword(s):  
Coalbed Methane ◽  
Environmental Risks ◽  
Risk Category ◽  
Burial History ◽  
Exploration And Exploitation ◽  
Coal Seams ◽  
Mining Operations ◽  
Environmental Threats ◽  
And Migration ◽  
Coal Macerals

In coal seams, depending on the composition of coal macerals, rank of coal, burial history, and migration of thermogenic and/or biogenic gas. In one ton of coal 1 to 25 m3 of methane can be accumulated. Accumulation of this gas is included in unconventional deposits. Exploitation of methane from coal seams is carried out with wells from mining excavations (during mining operations), wells drilled to abandoned coal mines, and wells from the surface to unexploited coal seams. Due to the low permeability of the coal matrix, hydraulic fracturing is also commonly used. Operations related to exploration (drilling works) and exploitation of methane from coal seams were analyzed. The preliminary analysis of the environmental threats associated with the exploration and exploitation of coalbed methane has made it possible to identify types of risks that affect the environment in various ways. The environmental risks were estimated as the product of the probability weightings of adverse events occurring and weightings of consequences. Drilling operations and coalbed methane (CBM) exploitation leads to environmental risks, for which the risk category falls within the controlled and accepted range.

Principle of Well-Net Design for Coalbed Methane Exploitation in Coal Mine Area

2014 ◽  
Vol 543-547 ◽  
pp. 3967-3973
Author(s):  
Bao Shan Han
Keyword(s):  
Coal Mining ◽  
Coal Mine ◽  
Coalbed Methane ◽  
Design Theory ◽  
Surface Condition ◽  
Coal Pillar ◽  
Negative Influence ◽  
In Situ Stress ◽  
Well Location

There are abundant CBM (Coalbed Methane) in China. These CBM has caused a remarkable problem to the coal-mining in China. In order to improve the structure of Chinese energy and eliminate the risk of coal mine gas, the relevant industries and sections have implemented many explorations in CBM enriched areas. With great achievements, there are many important problems in the actions of CBM exploitation. The disadvantageous interaction of the surface CBM well and the later coal mining has been ignored at all. There are many disadvantages and defects. To solve these problems and eliminate or weaken the disadvantageous, the scientific and reasonable design of surface CBM well location is an important step. With the thinking of surface condition, coal mining plan, the arrangement of coal mine laneway, the direction and scale of the in-situ stress, and thinking more about the negative influence to and of surface CBM well, according to the theories of mining dynamics, mining engineering, mining geomechanics, and the CBM engineering, the design theory of the surface CBM well net can be studied. Finally, the arrangement principle of CBM product well in coal field is presented. The existing or future coal pillar will be a critical location for the surface CBM well location.

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