Determination of the Size of the Fracture Zone Around a Road Working Based on the Results of Underground Convergence Measurements and Numerical Modelling

2008 ◽  
pp. 125-136
Author(s):  
Stanislaw Prusek
Keyword(s):  
Numerical Modelling ◽  
Fracture Zone

scholarly journals Determination of Long Horizontal Borehole Height in Roofs and its Application to Gas Drainage

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2647
Author(s):  
Gang Wang ◽  
Cheng Fan ◽  
Hao Xu ◽  
Xuelin Liu ◽  
Rui Wang
Keyword(s):  
Numerical Simulation ◽  
Theoretical Model ◽  
Fracture Zone ◽  
Coalbed Methane ◽  
High Efficiency ◽  
Gas Drainage ◽  
Methane Drainage ◽  
Working Face ◽  
Variation Characteristics

Accurately determining the height of the gas-guiding fracture zone in the overlying strata of the goaf is the key to find the height of the long horizontal borehole in the roof. In order to determine the height, in this study we chose the 6306 working face of Tangkou Coal Mine in China as a research example and used both the theoretical model and discrete element method (DEM) numerical simulation to find the height of the gas-guiding fracture zone and applied the height to drill a long horizontal borehole in the roof of the 6303 working face. Furthermore, the borehole was utilized to deep into the roof for coalbed methane drainage and the results were compared with conventional gas drainage measures from other aspects. The height of the gas-guiding fracture zone was found to be 48.57 m in theoretical model based on the bulk coefficient and the void ratio and to be 51.19 m in the DEM numerical simulation according to the temporal and spatial variation characteristics of porosity. Taking both the results of theoretical analysis and numerical simulation into consideration, we determined that gas-guiding fracture zone is 49.88 m high and applied it to drill a long horizontal borehole deep into the roof in the 6303 working face field. Compared with conventional gas drainage measures, we found that the long horizontal borehole has the high stability, high efficiency and strong adaptability for methane drainage.

Numerical modelling of a microreactor for thermocatalytic decomposition of toxic compounds

2011 ◽  
Vol 32 (3) ◽  
pp. 215-227 ◽  
Author(s):  
Paweł Jóźwik ◽  
Michał Karcz ◽  
Janusz Badur
Keyword(s):  
Numerical Modelling ◽  
Knudsen Diffusion ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Three Dimensional Model ◽  
Toxic Compounds ◽  
Slip Boundary ◽  
Standard Models ◽  
Thermocatalytic Decomposition

Numerical modelling of a microreactor for thermocatalytic decomposition of toxic compounds In this paper a three-dimensional model for determination of a microreactor's length is presented and discussed. The reaction of thermocatalytic decomposition has been implemented on the base of experimental data. Simplified Reynolds-Maxwell formula for the slip velocity boundary condition has been analysed and validated. The influence of the Knudsen diffusion on the microreactor's performance has also been verified. It was revealed that with a given operating conditions and a given geometry of the microreactor, there is no need for application of slip boundary conditions and the Knudsen diffusion in further analysis. It has also been shown that the microreactor's length could be practically estimated using standard models.

Seismic monitoring of the growth of a hydraulic fracture zone at Fenton Hill, New Mexico

Geophysics ◽  
1998 ◽  
Vol 63 (1) ◽  
pp. 120-131 ◽  
Author(s):  
Yingping Li ◽  
Chuen H. Cheng ◽  
M. Nafi Toksöz
Keyword(s):  
Hydraulic Fracturing ◽  
Hydraulic Fracture ◽  
Fracture Zone ◽  
Geothermal Energy ◽  
Solid Waste Disposal ◽  
Hydrocarbon Recovery ◽  
Tight Cluster ◽  
Grid Search Method ◽  
Subsurface Fractures

The hydraulic fracturing technique is an important method for enhancing hydrocarbon recovery, geothermal energy extraction, and solid waste disposal. Determination of the geometry and growth process of a hydraulic fracture zone is important for monitoring and assessing subsurface fractures. A relative‐source‐location approach, based on a waveform correlation and a grid search method, has been developed to estimate relative hypocenter locations for a cluster of 157 microearthquakes induced by hydraulic fracturing at the Los Alamos Hot Dry Rock (HDR) geothermal site. Among the 157 events, 147 microearthquakes occurred in a tight cluster with a dimension of 40 m, roughly defining a vertical hydraulic fracture zone with an orientation of N40°W. The length, height, and width of the hydraulic fracture zone are estimated to be 40, 35, and 5 m, respectively. Analysis of the spatial‐temporal pattern of the induced microearthquakes reveals that the fracture zone grew significantly, averaging 0.2 m/minute in a two‐hour period toward the northwest along the fracture zone strike.

Application of numerical modelling for assessing electric and thermal operation modes of direct current catenary elements

2020 ◽  
pp. 90-93
Author(s):  
Andrey Borisovich Batrashov ◽  
◽  
Natalya Vladimirovna Gushhina ◽  
Keyword(s):  
Numerical Modelling ◽  
Direct Current ◽  
Thermal Characteristics ◽  
Thermal Loads ◽  
Main Principle ◽  
Thermal Operation ◽  
Operation Conditions ◽  
Operation Modes ◽  
Digital Copy

The paper proposes a method for assessing electric and thermal operation modes of direct current catenary elements that allows determining electric and thermal loads in operation conditions. The main principle is the determination of the most loaded section in the intersubstational zone and calculation of electric and thermal characteristics in conditions of real train schedule. The method is assumed to be used at digitalization of railways as a digital copy of direct current catenary.

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