Results 41 to 50 of about 152 (101)

Research on Hydraulic Thruster-Enhanced Permeability Technology of Soft Coal Drilling through Strata Based on Packer Sealing Method

, 2023
According to the characteristics of “Three Soft” outburst coal seams in the Henan area with large gas content, poor air permeability, and extremely difficult extraction, the hydraulic fracturing and punching technology of soft coal with ...
Zhuangzhuang Yao, Linchao Dai, Zhigang Zhang   +2 more
core   +1 more source

Research and application of key technology of automatic drilling machine in soft coal seam

Meikuang Anquan
In order to solve the problems of spout hole, collapse hole, plugging hole and buried drilling in gas extraction drilling operation in broken soft coal seam, a type of ZDY4500LFK automatic drilling machine suitable for broken soft coal seam is developed.
Peilin CHEN
doaj   +1 more source

Study on the Synchronous Instability Mechanism of the Coal Wall and Direct Roof of High Soft Coal Seam

, 2022
The advanced mining stress on a large working face can easily lead to the failure of the roof and coal mass; coal wall spalling and roof caving occur. The degree of coal wall failure and the depth of the plastic fracture zone are closely related to the ...
Min Tu, Ningping Jin, Baojie Fu, Jiawen Li   +3 more
core   +1 more source

Real‐time lithology identification while drilling based on drill cuttings image analysis with ensemble learning

Deep Underground Science and Engineering, EarlyView.
A lithology identification while drilling method was developed, integrating an automated cuttings sampling system, a smart drilling rig, and an ensemble learning model. Underground trials achieved 97.42% accuracy in real‐time identification of cuttings lithology and composition, enhancing hazard management and supporting unmanned drilling technology in
Kun Li, Ting Ren, Ningping Yao, Jon Roberts, Haitao Song, Zhongbei Li, Xueqiu He, Liang Zhao   +7 more
wiley   +1 more source

Study on the model of staged and cluster fracturing to control the gas in driving roadway by horizontal well in roof strata

Meitan kexue jishu
To address the issue of low gas extraction efficiency in driving roadway of broken soft and low permeability coal seams in Huainan mining area, a model of segmented cluster fracturing gas management in horizontal wells at the roof of coal seams was ...
Bo WANG, Enke HOU, Liang MA, Siqing SUN, Xinfeng DU, Jianchao YANG, Zhengxi WANG, Yuanwei SHAN   +7 more
doaj   +1 more source

Multiple injection techniques to stimulate complex fracture networks in coal reservoirs: A case study on gas disaster reduction of subsurface coal mine in southwest China

Deep Underground Science and Engineering, EarlyView.
An experimental device for physical simulation of hydraulic fracturing, comprising: a load‐bearing mechanism with multiple interconnected plates that collectively form an sample chamber; a load‐generating mechanisms, with multiple load‐generating mechanisms arranged within the experimental chamber.
Delei Shang, Farui Shi, Jun Lu, Minghui Li, Cunbao Li, Heping Xie   +5 more
wiley   +1 more source

Fracture evolution of a thick soft protection layer and the water inrush mechanism in overburden under longwall mining

Deep Underground Science and Engineering, EarlyView.
Through shear–tensile creep tests and viscoelastic modeling, the fracture evolution of thick soft protective layers is clarified. Results show thickness‐dependent rheological failure modes that govern four types of roof water inrush, providing a mechanism‐based framework for hazard prediction and control. Abstract In the Jurassic coal‐bearing strata of
Mengnan Liu, Wei Qiao, Xianggang Cheng, Xiangsheng Meng, Peichao Feng   +4 more
wiley   +1 more source

Multi-azimuth minimal radius punching technology for strata-penetrating borehole of underground coal mine

Meikuang Anquan, 2023
The broken and soft coal seam has high gas content and poor permeability. The single hole drainage radius is small when the conventional through-bed drilling is used for gas drainage, and the drilling engineering volume is large.
Tao PANG, Zaibing JIANG, Tianlin DU, Haozhe LI, Jiajia ZHOU, Wei LIU   +5 more
doaj   +1 more source

First occurrences of Trionychidae (Testudines, Cryptodira) from the Miocene of Poland: Detailed cranial anatomy and biogeographic implications

Journal of Anatomy, EarlyView.
Fossil finds from three Middle Miocene sites in Poland reveal the northernmost known presence of trionychid turtles in Europe, tentatively identified as Trionyx cf. vindobonensis, suggesting a warmer climate that supported thermophilic species in Central Europe during this period. Abstract Modern trionychids (Testudines, Cryptodira) have a pan‐tropical
Yohan Pochat‐Cottilloux, Sergi López‐Torres, Milan Chroust, Georgios L. Georgalis, Marcin Górka, Mateusz Tałanda   +5 more
wiley   +1 more source

The Unexpected Discovery of Paleocene? Coals in Outcrops Thought to Be Cambrian, Al Huqf, Oman

Journal of Petroleum Geology, EarlyView.
ABSTRACT Two brown organic deposits were encountered whilst investigating kaolinitic claystones thought to occur at the base of a Cambrian formation at outcrop. The age of these organic deposits is probably Paleocene from palynology. Organic petrography shows that they are subbituminous coals with some oil source potential.
Mohammed H. Al Kindi, Alan P. Heward, Lorraine B. Eglinton, Steve R. Packer, Darrin T. Stead   +4 more
wiley   +1 more source