An underground coal mine medium frequency (MF) communication system generally couples its electromagnetic signals to a long conductor in a tunnel, which acts as a transmission line, and exchanges signals with transceivers along the line. The propagation characteristics of the transmission line, which is usually the longest signal path for an MF communication system, play a major role in determi...

The clear understanding of hydraulic fracture network complexity and the optimization of fracture network configuration are important to the hydraulic fracturing treatment of shale gas reservoirs. For the prediction of hydraulic fracture network configuration, one of the problems is the accurate representation of natural fractures. In this work, a real natural fracture network is reconstructed ...

Nowadays, one of the main tasks of Ukrainian coal industry is increasing labour productivity by means of complex mechanization and automatization of mining operations with usage of modern equipment. The best example is implementation of modern plow complexes on Western Donbas mines, PJSC “DTEK Pavlogradvugillia”. Currently, plowing is one of perspective directions of coal extraction development...

Natural gas is lauded as a cleaner-burning fuel than either coal or oil, but getting the fuel out of the ground can be a dirty process, especially given the widespread adoption of the technology known as hydraulic fracturing (" fracking "). Concerns about toxic air emissions from previously unregulated fracking sites led to the U.S. Environmental Protection Agency announcement on 18 April 2012 ...

Aquifer test methods have greatly improved in recent years with the advent of inverse analysis, derivative analysis, and diagnostic plots. Updated analyses of past aquifer tests allow for improved interpretations of the data to enhance the knowledge and the predictive capabilities of the flow system. This work thoroughly reanalyzes a series of preand post-hydraulic fracturing, single-well aquif...

Abstract As an unconventional oil and gas resource, coalbed methane has become a key area of exploration worldwide, hydraulic fracturing is the critical technology for efficient stimulation methane. However, due to strong heterogeneity deep coal seam reservoirs development natural cleat fractures, fracture propagation path quite complex difficult capture. In this study, we propose simulation me...

Lithological characteristics, mineral composition, physical properties of water and physical and mechanical properties, weathering zone distribution and other factors of bedrock weathering zone in coal-seam roof determine the strength of its watertight performance, while its performance has a direct impact on impermeable overlying loose surface water aquifers as well as the possible collapse in...

Rock fracture propagation is a major hazard for mining and tunnel excavation in fractured rock masses or coal seams. A longwall panel with typical dimension of 200m (width)×1000m (length)×3m (height) can be considered as an open edge crack. The fracturing processes the vicinity crack (or panel) particularly roof floor are critically important safety operation because lead to water inrush dynami...

In this paper, the mechanical behaviors of different lithological rocks coal measure strata from Shanxi Formation in eastern margin Ordos Basin, China, were investigated through uniaxial compression tests, and deformation characteristics failure modes investigated. On basis, energy evolution lithology was also discussed. The results show that there are obvious differences properties strata, res...

Automation in underground mining enhances safety and leads to economic efficiencies. After more than 50 years of research, automation tasks have gradually been growing out of the classic engineering/mechanical environment and require a sophisticated datamining treatment. The success of (mechanical) process automation has left only one remaining place in the coal-excavation process where human l...