Preliminary degassing of burst-prone coal seams by means of large-diameter boreholes

1970 ◽  
Vol 6 (1) ◽  
pp. 1-8 ◽  
Author(s):  
V. V. Khodot ◽  
V. G. Krupenya ◽  
G. G. Stepchenkova
Keyword(s):  
Large Diameter ◽  
Coal Seams ◽  
Preliminary Degassing

MINE STUDIES OF IMPROVED TECHNOLOGY OF UNDERGROUND FRACTURING OF COAL SEAMS FOR THE PURPOSE OF EFFICIENT PRELIMINARY DEGASSING

2018 ◽  
Vol 1 (3) ◽  
pp. 16-22
Author(s):  
E.V. Mazanik ◽  
◽  
A.V. Ponizov ◽  
S.V. Slastunov ◽  
P.N. Paschenkov ◽  
...  
Keyword(s):  
Coal Seams ◽  
Improved Technology ◽  
Preliminary Degassing

Calculation of the fall in gas pressure during degassing of thin coal seams by large-diameter boreholes

1972 ◽  
Vol 8 (3) ◽  
pp. 291-295 ◽  
Author(s):  
V. V. Khodot ◽  
R. N. Isaeva ◽  
V. G. Krupenya
Keyword(s):  
Large Diameter ◽  
Gas Pressure ◽  
Coal Seams

scholarly journals Research on Optimization of Coal Pressure Relief Borehole Parameters under High-Stress Conditions

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Heng Zhang ◽  
Tie Li ◽  
Zhenhua Ouyang ◽  
Su Liu ◽  
Haiyang Yi
Keyword(s):  
Stress Concentration ◽  
Energy Density ◽  
Elastic Energy ◽  
Large Diameter ◽  
High Stress ◽  
Stress Conditions ◽  
Plastic Behavior ◽  
Coal Seams ◽  
Pressure Relief ◽  
Relief Area

Determining the parameters of boreholes drilled for relieving pressure in coal seams is the key preventing and controlling rock bursts in boreholes of large diameter. In this study, theoretical analysis, numerical simulation, literature research, and other analysis methods are applied to study the angles of elastic energy dissipation and stress transfer, the distribution law of the pressure relief area, and the areas of stress concentration, energy, stress, displacement, and plastic behavior of large-diameter pressure relief boreholes in coal seams under high-stress conditions. The results are then used to evaluate the relationship between large-diameter pressure relief boreholes and the borehole arrangement. The following results are obtained. (1) A large-diameter results in a large amount of elastic energy released by the surrounding coal, low residual elastic energy density, strong interaction between boreholes, large pressure relief range of the borehole, and high pressure relief efficiency. (2) The main evaluation factor of the borehole pressure relief effect is its thickness and stress concentration area; secondary evaluation is based on the areas of energy, displacement, stress, and plastic behavior. (3) Six evaluation index systems are established to evaluate the effects of borehole pressure relief, which are found to be the thicknesses of the borehole pressure relief area and stress concentration area, reduction degree of energy density, percentage of stress reduction, displacement, and penetration degree of the plastic area. (4) It is determined that when the diameters of the pressure relief boreholes are 100, 120, 180, and 200 mm, a single-row borehole arrangement is adopted; a three-pattern borehole arrangement is adopted with diameters of 140 and 160 mm. These research results can provide theoretical support in selecting reasonable borehole arrangements for pressure relief boreholes of different diameters.

scholarly journals RISK REDUCTION ESTIMATION FOR UNDERGROUND MINING OF GAS-CONTAINED COAL SEAMS WHILE USING THE HYDRAULIC FRACTURING

2019 ◽  
Vol 2 (5) ◽  
pp. 3-11
Author(s):  
Sergey Serdyukov ◽  
Tatiana Shilova ◽  
Leonid Rybalkin
Keyword(s):  
Comparative Analysis ◽  
Coal Seam ◽  
Hydraulic Fracturing ◽  
Risk Reduction ◽  
Underground Mining ◽  
Coal Seams ◽  
Filtration Resistance ◽  
Different Types ◽  
Interval Hydraulic Fracturing ◽  
Preliminary Degassing

In the paper, influence of hydraulic fracturing parameters on filtration resistance of system of parallel holes during preliminary degassing of coal seam loaded with strata pressure is considered. Results of comparative analysis of degassing rates of coal seam while using holes without hydraulic fracturing and holes with non-directed or plural interval hydraulic fracturing of various orientation are represented. Estimation of influence of fracturing of different types on risk reduction of underground mining of gas-contained coal seams is given. Obtained results allow to estimate perspective of application of present modifications of hydraulic fracturing technology at coal mines.

scholarly journals Regional Outburst-prevention Technique by Gas Pre-drainage Based on Large Diameter Boreholes along Coal Seams under Deep Mining

2011 ◽  
Vol 26 ◽  
pp. 623-629 ◽  
Author(s):  
Liu Yanwei ◽  
Liu Mingju ◽  
Wei Jianping
Keyword(s):  
Large Diameter ◽  
Coal Seams ◽  
Deep Mining

Drilling large diameter cross-measure boreholes to improve gas drainage in highly gassy soft coal seams

2015 ◽  
Vol 26 ◽  
pp. 193-204 ◽  
Author(s):  
Yabin Gao ◽  
Baiquan Lin ◽  
Wei Yang ◽  
Ziwen Li ◽  
Yuan Pang ◽  
...  
Keyword(s):  
Large Diameter ◽  
Coal Seams ◽  
Gas Drainage ◽  
Soft Coal

scholarly journals Methane Emission Control at the High-Productive Longwall Panels of the Yalevsky Coal Mine

2020 ◽  
Vol 174 ◽  
pp. 01040
Author(s):  
Anatoly Meshkov ◽  
Oleg Kazanin ◽  
Andrey Sidorenko
Keyword(s):  
Methane Emission ◽  
Emission Control ◽  
Gas Content ◽  
Kuznetsk Coal ◽  
Vertical Wells ◽  
Coal Seams ◽  
High Productivity ◽  
Zone Of Influence ◽  
Preliminary Degassing ◽  
Gas Suction

The analysis of the experience of methane emission control at the V. D. Yalevsky mine (Kuznetsk coal basin, Russia) during the series of shallow gassy coal seams mining with the high productive longwall was performed. The analysis of the efficiency of gob degassing by the vertical wells and isolated methane removal by gas-suction fans is performed. The efficiency of reducing the distance between ventilation crosscuts between entries is shown. It is also shown that the problems of providing the longwall high productivity in conditions of increasing the natural gas content in the coal seams are associated with gas emission from the extracted coal seam and the lack of effective methods for its early and preliminary degassing. Recommendations for using advanced mining of close-up coal seams as an effective method of degassing of rock mass within the zone of influence of undermining and overmining are given.

Development of a digital SEM

1991 ◽  
Vol 49 ◽  
pp. 358-359
Author(s):  
A. Yamada ◽  
A. Shibano ◽  
K. Harasawa ◽  
T. Kobayashi ◽  
H. Fukuda ◽  
...  
Keyword(s):  
Large Diameter ◽  
Objective Lens ◽  
Large Specimen ◽  
Backscattered Electrons ◽  
Digital Scanning ◽  
Junction Type ◽  
High Resolution Images ◽  
Working Distance ◽  
Type Detector ◽  
Short Working

A newly developed digital scanning electron microscope, the JSM-6300, has the following features: Equipped with a narrower conical objective lens (OL), it allows high resolution images to be obtained easily at a short working distance (WD) and a large specimen tilt angle. In addition, it is provided with automatic functions and digital image processing functions for ease of operation.Conical C-F lens: The newly developed conical C-F objective lens, having low aberration characteristics over a wide WD range, allows a large-diameter (3-inch) specimen to be tilted up to 60° at short WD, and provides images with low magnifications starting at 10*. On the bottom of the lens, a p n junction type detector is provided to detect backscattered electrons (BE) from the specimen. As the narrower conical 0L increases the secondary electron (SE) detector's field intensity on the specimen surface, high SE image quality is obtained.

Sign in / Sign up

Export Citation Format

Share Document