Results 71 to 80 of about 152 (101)

Parameter optimization and field application of roof volume fracturing using horizontal wells for coalbed methane extraction from broken-soft coal seams

Meitian dizhi yu kantan
Objective and MethodTo achieve rapid coalbed methane (CBM) extraction from broken-soft coal seams using surface horizontal wells, this study proposed a volume fracturing technology for coal seam roof using horizontal wells.
Qingli ZHANG, Siqing SUN, Haozhe LI, Xiaoxuan WU, Fan YANG, Yuqi ZHENG, Wenbo LI   +6 more
doaj   +1 more source

Relationship between in situ coal stratigraphy and particle size and composition after breakage in bituminous coals

, 2002
The hypothesis that the parent stratigraphy of a coal seam, i.e. its lithotype and band distribution, can be used to estimate the input and output size distributions of broken coal for a fragmentation event(s) was tested using the drop-shatter process ...
G O'Brien, Y Kolatschek, Kolatschek, Y., J.S Esterle, Esterle, J. S., O’Brien, G.   +5 more
core   +1 more source

Development characteristics of loose karst collapse columns and their transformation effect on coal properties and coal quality

Meikuang Anquan
Karst collapse column is one of the main geological factors that cause hidden disasters in many coal fields in North China. Especially, when the columns are soft and fractured, they will make great challenges to exploration, prevention, and safety ...
Heping LIU, Shuaifeng LYU, Xiao YANG, Chong CHEN, Zhangkai XIONG, Shuai MA   +5 more
doaj   +1 more source

Dynamic compression mechanical properties of soft coal under different strain rates

Meitan kexue jishu
The disturbance of deep impact loading can easily induce the instability accident of surrounding rock in soft coal seam. In order to study the dynamic mechanical characteristics of soft coal under different strain rates, aiming at the soft coal of 11518 ...
Chuanqi ZHU, Lei WANG, Huaiqian LIU, Lipeng CHEN, Shuai ZHANG   +4 more
doaj   +1 more source

Influence of natural weak surface on extension of multiple fractures during fracturing of gas extraction horizontal wells

Meitan kexue jishu
In view of the difficult problem of strip gas extraction in coal roadways of broken soft and low permeability coal seam, this paper puts forward the technology of segment fracturing and high efficient pre-gas extraction in horizontal wells of strip roof ...
Tao PANG, Zaibing JIANG, Zhengxi WANG, Xiugang LIU, Haozhe LI   +4 more
doaj   +1 more source

Key technologies and management of arc section in full-mechanized caving face for "three soft" ultra-thick coal seam with large dip angle

Meitan kexue jishu
At present, there are still some long-term unsolved problems in full-mechanized caving mining technology of "three soft" ultra-thick coal seam with large dip Angle at home and abroad. The main performance is that the mining equipment dominated by support
Guirong HE, Ning WANG, Jun ZHANG
doaj   +1 more source

Experimental study on mechanical damage properties and energy evolution characteristics of coal-rock combination under different interface conditions

Earth Energy Science
Indirect fracturing technology is a crucial method for enhancing gas extraction efficiency in broken soft coal seams. The cracks initiate from the roof strata, traverse the coal-rock interface, and ultimately penetrate the coal seam. In this process, the
Tong Yang, Tao Yang, Chao Xu, Kai Wang, Tao Li   +4 more
doaj   +1 more source

Study on dynamic response law of gas drainage characteristics in cavity-making and permeability enhancement technology for loose and broken soft coal seams

Meikuang Anquan
Cavity-making technology in coal seams is one of the main technologies for controlling gas in loose, low-permeability, and difficult-to-drain coal seams.
Kai MA
doaj   +1 more source

Mine-Tunnel Design & Monitoring Analysis for Major Faults and Complex Geological Conditions

, 2013
Mining operations at Nanyang-Slope Coal Mine are considerably challenging. The Nanyang- Slope Coal Field has a complex tectonic structure; having major faults, large fissures and fracture- zones, and great changes in coal-seam thickness.
ZHANG, Xiang-dong, ZHANG, Yu, FAN, Shi-xing, ZHANG, Hu-wei   +3 more
core   +1 more source

Exploration and research progress on the integrated technology of coalbed methane development, gas control, and methane emission reduction

工程科学学报
Coal methane is a hydrocarbon gas with methane as its main component. This is a collective term for coalbed methane (CBM) and coal mine gas, which coexist with coal in coal seams.
Shuxun SANG, Honggao XIE, Zhihua YAN, Shiqi LIU, Xiaozhi ZHOU, Sijie HAN, Sijian ZHENG, Fansheng HUANG   +7 more
doaj   +1 more source