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Engineering Commons

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

2019

Physical Sciences and Mathematics

Journal

Coal Geology & Exploration

Coal seam

Articles 1 - 3 of 3

Full-Text Articles in Engineering

The Effect Of Viscoelasticity And Velocity Anisotropy On The Reflections Of A Thin Bed, Chen Benchi, Wang Chao, Chen Changxing, Shi Lei Oct 2019

The Effect Of Viscoelasticity And Velocity Anisotropy On The Reflections Of A Thin Bed, Chen Benchi, Wang Chao, Chen Changxing, Shi Lei

Coal Geology & Exploration

The coal seam is a typical thin bed characterized by much lower elastic impedance than that of the surrounding rock. Coal seam has viscoelasticity and velocity anisotropy and its reflection amplitude changes with frequency. In order to analyze the effect of viscoelasticity and velocity anisotropy on seismic responses of a thin bed, this paper aims at a thin-bed model with strong impedance contrast and simulates seismic responses under three different assumptions, elastic and velocity isotropy, viscoelastic and velocity isotropy, and viscoelastic and velocity anisotropy, through numerical simulation method based on wave equations. Comparison of these seismic reflections shows that the …


Corrosion Behavior Analysis Of Sucker Rod For Coalbed Methane Wells In The Eastern Block Of Ordos Basin, Pang Bin, Wang Hanxiang, Lan Wenjian Aug 2019

Corrosion Behavior Analysis Of Sucker Rod For Coalbed Methane Wells In The Eastern Block Of Ordos Basin, Pang Bin, Wang Hanxiang, Lan Wenjian

Coal Geology & Exploration

In order to make clear the corrosion rule of sucker rod for coalbed methane wells in the eastern block of Ordos basin, the paper summarizes the corrosion types and corrosion intensities of the sucker rod, based on the test of produced gas, produced water, corrosion products and weight loss of sucker rod. The paper analyzes the effect of different drainage stages, coal seam and mineralization degree of water on the corrosion. The results of the research indicate that corrosion is mainly caused by CO2 and H2S originated from No.5 coal seam and No.11 coal seam. The corrosion …


Instability Mechanism And Anti-Sloughing Drilling Fluid Technique For Deep Coal Seam Of Tarim Basin, Li Heng, He Shiming, Tang Ming, Li Ning, Yang Pei, Zhang Zhen Aug 2019

Instability Mechanism And Anti-Sloughing Drilling Fluid Technique For Deep Coal Seam Of Tarim Basin, Li Heng, He Shiming, Tang Ming, Li Ning, Yang Pei, Zhang Zhen

Coal Geology & Exploration

In view of the complicated problems of drilling fluid leakage and hole collapse during the drilling of deep coalbed in Tarim basin, the microstructure and physical and chemical properties of coal were tested by vitrinite reflectance analysis, X ray diffraction and scanning electron microscope, and the mechanism of coal seam instability was confirmed. The fixed carbon content of the coal exceeds 60%, the vitrinite reflectance is greater than 1.1%, and coal have high degree of coalification, is brittle and easy to break. The total amount of clay mineral is less than 25%, and there is no strong water-sensitive mineral montmorillonite …