Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Environmental Sciences

Coal Geology & Exploration

Fracture

Publication Year

Articles 1 - 9 of 9

Full-Text Articles in Engineering

Mechanisms And Technological Parameter Optimization Of Near-Wellbore Laser Thermal Fracturing For Deep Coal Seams, Zhao Haifeng, Yang Ziyi, Liang Wei, Zhong Junbing Feb 2024

Mechanisms And Technological Parameter Optimization Of Near-Wellbore Laser Thermal Fracturing For Deep Coal Seams, Zhao Haifeng, Yang Ziyi, Liang Wei, Zhong Junbing

Coal Geology & Exploration

China boasts abundant deep coalbed methane (CBM) resources, which play a significant role in further CBM production. However, deep coal seams exhibit low porosities and ultra-low permeabilities due to intricate geological conditions. In the drilling process, drilling fluids enter the reservoirs, prone to cause near-wellbore contamination. Although conventional hydraulic fracturing technology tends to create fractures in the direction of the maximum horizontal principal stress, it is challenging for this technology to achieve blockage removing throughout the whole borehole. Laser thermal fracturing technology can break rocks in a short time. Furthermore, it allows for the laser irradiation angle to change freely …


Experimental Study On The Influence Of Coal-Based Co2 Geological Storage On Roof Fracture Conductivity, Zhu Shiliang, Shao Liwei, Zhou Xiaozhi, Cao Yutong, Zhang Kun, Wang Jiandong Jun 2021

Experimental Study On The Influence Of Coal-Based Co2 Geological Storage On Roof Fracture Conductivity, Zhu Shiliang, Shao Liwei, Zhou Xiaozhi, Cao Yutong, Zhang Kun, Wang Jiandong

Coal Geology & Exploration

Coal-based CO2 geological storage is an important way to reduce greenhouse gas emissions, but there is also a safety risk of underground CO2 leakage. In order to evaluate the safety of coal-based CO2 geological storage, the roof samples of No.3 coal seam in Hudi Coal Mine, southern Qinshui Basin were collected, and the changes of artificial fracture morphology, whole rock mineral composition and CO2 conductivity of columnar samples in "CO2-H2O-Rock" reaction were studied by simulation experiments. The results show that calcite vein dissolution, secondary mineral filling and external effective stress jointly affect …


Research On The Evolution Law Of Roadway Surrounding Rock Fissure Based On Fractal Dimension, Ding Wanqi, Ma Zhenqian, Zu Ziyin, Xie Hongfei, Yang Wei, Chen Chuan Jun 2021

Research On The Evolution Law Of Roadway Surrounding Rock Fissure Based On Fractal Dimension, Ding Wanqi, Ma Zhenqian, Zu Ziyin, Xie Hongfei, Yang Wei, Chen Chuan

Coal Geology & Exploration

To explore the evolution law of surrounding rock fissures under the influence of horizontal stress and dynamic disturbance in argillaceous roadways, the deformation and failure characteristics of argillaceous roadways, the evolution law of surrounding rock fissures and the fractal evolution characteristics of surrounding rock fissures under dynamic disturbance are studied by such methods as field investigation, numerical simulation and fractal theory analysis, with the 226 track gate of Shanjiaoshu Mine in Panzhou City as the engineering background. The results show that before dynamic disturbance, the expansion range of fracture zone and plastic zone of roadways gradually increases with the increase …


Improvement And Optimization Of Permeability And Strength Properties Of Loess, Zhu Min, Ni Wankui, Yuan Kangze, Li Lan, Li Xiangning, Wang Haiman Dec 2020

Improvement And Optimization Of Permeability And Strength Properties Of Loess, Zhu Min, Ni Wankui, Yuan Kangze, Li Lan, Li Xiangning, Wang Haiman

Coal Geology & Exploration

In order to study the development of secondary faults and fracture, a boundary element method (BEM) combined with seismic interpretation of main faults and geo-mechanics is discussed. Firstly, with the Anderson's theory of faulting, the classification of secondary fault tectonic evolution events is improved under the combination of fault and stress; secondly, the stress tensor order reduction and linear superposition principle are applied to simplify the stress and displacement balance equation, and the Monte Carlo method is used to inverse the paleo-stress field. After all, the equilibrium equation of stress, strain and discontinuous displacement is solved to obtain the current …


Application Of Broadband And Wide Azimuth Processing Technology In Full Digital High Density Seismic Exploration In Huaibei Mining Area, Yang Guangming, Jin Xueliang, Zhang Xianxu, Zhi Min, Shan Rui Dec 2020

Application Of Broadband And Wide Azimuth Processing Technology In Full Digital High Density Seismic Exploration In Huaibei Mining Area, Yang Guangming, Jin Xueliang, Zhang Xianxu, Zhi Min, Shan Rui

Coal Geology & Exploration

During coalbed methane well drilling, the drilling fluid contaminates and blocks the pores and fractures of coal seam. In order to find out the difference of pollution degree of drilling fluid coal and the contribution rate of the pores and fractures of different scale to permeability, the coal of Changping mine was taken as the research object, the scanning electron microscopy(SEM) and the Image Pro Plus(IPP) processing technology were used, the parameters such as the average length, the average width, the total area and the total perimeter of the fractures of different scales in coal before and after contamination were …


Quantitative Evaluation Of The Contamination Degree Of The Drilling Fluid For Fractures Of Different Scale In Coal, Zhang Jingshuo, Ni Xiaoming, Li Yang, Li Zongyuan, Cao Yunxing Oct 2020

Quantitative Evaluation Of The Contamination Degree Of The Drilling Fluid For Fractures Of Different Scale In Coal, Zhang Jingshuo, Ni Xiaoming, Li Yang, Li Zongyuan, Cao Yunxing

Coal Geology & Exploration

During coalbed methane well drilling, the drilling fluid contaminates and blocks the pores and fractures of coal seam. In order to find out the difference of pollution degree of drilling fluid coal and the contribution rate of the pores and fractures of different scale to permeability, the coal of Changping mine was taken as the research object, the scanning electron microscopy(SEM) and the Image Pro Plus(IPP) processing technology were used, the parameters such as the average length, the average width, the total area and the total perimeter of the fractures of different scales in coal before and after contamination were …


Experiment Of Secondary Fault Information Mining Based On Boundary Element Method, Lu Ziqing, Zhu Shujie, Zhang Xiaowen, Wang Ji Oct 2020

Experiment Of Secondary Fault Information Mining Based On Boundary Element Method, Lu Ziqing, Zhu Shujie, Zhang Xiaowen, Wang Ji

Coal Geology & Exploration

In order to study the development of secondary faults and fracture, a boundary element method (BEM) combined with seismic interpretation of main faults and geo-mechanics is discussed. Firstly, with the Anderson's theory of faulting, the classification of secondary fault tectonic evolution events is improved under the combination of fault and stress; secondly, the stress tensor order reduction and linear superposition principle are applied to simplify the stress and displacement balance equation, and the Monte Carlo method is used to inverse the paleo-stress field. After all, the equilibrium equation of stress, strain and discontinuous displacement is solved to obtain the current …


Ruger Approximate Formula-Based Prediction Of Fractured Reservoir, Wu Shanshan, Gao Gang, Gui Zhixian, Wang Peng, Li Chengyi Feb 2020

Ruger Approximate Formula-Based Prediction Of Fractured Reservoir, Wu Shanshan, Gao Gang, Gui Zhixian, Wang Peng, Li Chengyi

Coal Geology & Exploration

The azimuthal anisotropy of pre-stack P-wave is the most widely used method to detect fracture. This method mainly uses the long-axis and minor axis information of the ellipse fitted by the AVAZ seismic data to evaluate the fracture. When applying it in practice, it is considered that the variation of AVAZ response characteristics in the fractured reservoirs is just determined by the anisotropic parameters, and the influence of non-anisotropic parameters is not taken into account, which leads to the multi-solution of fracture evaluation. In order to improve the accuracy of this fracture evaluation technology, we started with the model analysis, …


Fluid Factor Of Fracture And Seismic Velocity Response In Anisotropic Coal Beds, Li Qin, Ma Suibo, Zhao Bin Dec 2019

Fluid Factor Of Fracture And Seismic Velocity Response In Anisotropic Coal Beds, Li Qin, Ma Suibo, Zhao Bin

Coal Geology & Exploration

The storage and transport of gas and water in coal seam are related to the density, strike and filler of cracks. Research on the identification and prediction of coal seam cracks will be helpful to prevent and control disastrous accidents in coal mines, such as water inrush and gas outburst. It plays an important role in the safety evaluation of coal mining. Based on the theory of fracture equivalent model, the variation characteristics of fluid factor in coal seam crevices with different fillings and fracture weaknesses parameters(fracture density, aspect ratio, volume modulus, shear modulus, Lamé parameters) are analyzed by combining …