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Journal

2023

Pressure-preserved coring

Articles 1 - 8 of 8

Full-Text Articles in Engineering

Sealing Performance Analysis And Structure Optimization Of Pressure-Preserved Controller For Pressure-Preserved Coring In Deep Coal Mine, Wang Tianyu, Li Jianan, Zhang Yiwei, Li Ju, Xie Heping Aug 2023

Sealing Performance Analysis And Structure Optimization Of Pressure-Preserved Controller For Pressure-Preserved Coring In Deep Coal Mine, Wang Tianyu, Li Jianan, Zhang Yiwei, Li Ju, Xie Heping

Coal Geology & Exploration

As the pressure-preserved controller is a core component of the deep coal in-situ pressure-preserved coring device, its sealing design plays a decisive role in the effect of pressure-preserved coring. In order to obtain the optimal sealing structure, a two-dimensional axisymmetric nonlinear contact model was established for the sealing structure of the pressure-preserved controller. On this basis, the effects of different groove design, cone angle selection and friction coefficient on the sealing performance were analyzed by orthogonal test method. Meanwhile, the stress changes of the sealing ring under different closing stages and medium pressures were studied. The results show that: the …


R&D And Experimental Research Of Pressure-Preserved Triggering Device For Horizontal Pressure-Preserved Coring In Coal Mines, Huang Wei, Chen Ling, Li Jianan, Fan Dong, Yang Mingqing, Liu Guikang, Xu Qing, Ma Changliang Aug 2023

R&D And Experimental Research Of Pressure-Preserved Triggering Device For Horizontal Pressure-Preserved Coring In Coal Mines, Huang Wei, Chen Ling, Li Jianan, Fan Dong, Yang Mingqing, Liu Guikang, Xu Qing, Ma Changliang

Coal Geology & Exploration

Gas content is an important evaluation index of safe coal mining, as well as the exploitation and utilization of coalbed methane resources. Pressure-preserved coring is an effective way to improve the measurement accuracy of gas content in coal seams. Aiming at the special operating conditions of horizontal pressure-preserved coring in coal mines and based on the principle and technology of pressure- and gas-preserved coring in coal mines, this study developed a pressure-preserved triggering device and systematically designed the key components of the device, such as the sealing and pressure-preserved unit, the hydraulic drive module, and the salvager-unstuck mechanism between the …


Closure Trajectory Model Of Pressure-Preserved Controller For Coring In Coal Seam Surface Well, Guo Da, Zhang Yiwei, Wang Dingming, Fang Xin, Yang Bengao, Guo Lihua, Hou Lele, Zhao Xiang Aug 2023

Closure Trajectory Model Of Pressure-Preserved Controller For Coring In Coal Seam Surface Well, Guo Da, Zhang Yiwei, Wang Dingming, Fang Xin, Yang Bengao, Guo Lihua, Hou Lele, Zhao Xiang

Coal Geology & Exploration

The traditional method of coal exploration is to obtain coal samples using an open coring tool and estimate the gas loss through theoretical calculations. However, the measured gas content of these coal samples is generally low, significantly impeding the development and utilization of coalbed methane and compromising the safety of coal mining operations. To meet the demands of deep coal exploration, an innovative pressure-preserved coring tool was specifically designed for the coal seam surface wells. This tool has a total length of 6.7 m and can extract a 3 m long pressure-preserved coal core sample at a single time. In …


Research Advances On The In-Situ Pressure-Preserved Coring And Gas Parameter Determination For Deep Coal Seams, Xie Heping, Cui Pengfei, Shang Delei, Fan Dong, Chen Ling, Yang Mingqing, Du Lin, Gao Mingzhong Aug 2023

Research Advances On The In-Situ Pressure-Preserved Coring And Gas Parameter Determination For Deep Coal Seams, Xie Heping, Cui Pengfei, Shang Delei, Fan Dong, Chen Ling, Yang Mingqing, Du Lin, Gao Mingzhong

Coal Geology & Exploration

The in-situ gas pressure and content of coal seams are critical for the safe production of deep coal mines and the accurate evaluation of coalbed methane resources. To address the technical challenges of accurately determining in-situ gas content in deep coal seams, this study proposed brand-new principles of in-situ pressure coring and the tests of in-situ gas content and pressure. It also derived a calculation method for in-situ gas content in coal seams and a method for determining the in-situ gas pressure while considering the effects of moisture content and multiple gas components. Given the in-situ stress environment deep in …


Development Of Self-Locking Transfer Mechanism For Coal Samples From Pressure-Preserved Coring In Deep Mining, Zhu Pengfei, Li Jianan, Li Ju, Fu Chenghang, Ye Banghua Aug 2023

Development Of Self-Locking Transfer Mechanism For Coal Samples From Pressure-Preserved Coring In Deep Mining, Zhu Pengfei, Li Jianan, Li Ju, Fu Chenghang, Ye Banghua

Coal Geology & Exploration

Pressure-preserved coring technology can directly store the collected deep coal samples at the bottom of the hole, so as to minimize the gas loss during the coring process. Besides, pressure transfer and testing of the pressure-preserved rock core is a technical prerequisite for the accurate determination of gas content. Then, how to achieve the precise docking from pressure-preserved coring to pressure transfer and testing has become a key technical difficulty that needs to be overcome urgently. Therefore, the research was carried out around the self-locking transfer mechanism, which is the core component of the docking transfer between the pressure-preserved coring …


Influence Of Gas Components On The Determination Of Gas Pressure In Coal Seams Under In-Situ Pressure-Preserved Coring, Chu Peng, Shang Delei, Li Jianhua, Ma Shaoming, Zhu Guodong, Cui Pengfei Aug 2023

Influence Of Gas Components On The Determination Of Gas Pressure In Coal Seams Under In-Situ Pressure-Preserved Coring, Chu Peng, Shang Delei, Li Jianhua, Ma Shaoming, Zhu Guodong, Cui Pengfei

Coal Geology & Exploration

Determining the pressure and content of coal seam gas based on pressure-preserved coring is an effective method for quickly and accurately calculating gas parameters. Coal seam gas is a multi-component gas mixture dominated by methane. Given that coals show different adsorption capacities for different gases and that the components in the mixed gas exhibit different partial pressures, the proportions of gas components can influence the calculation results of the content and pressure of coal seam gas. To accurately determine the in-situ gas pressure in coal seams based on the pressure-preserved coring, this study investigated the influence of gas components on …


Simulation Optimization And Applications Of Pressure-Preserved Triggering Device For Coring In Deep Coal Mines, Shi Xiaojun, Li Minghui, Liu Guikang, You Zhenxi, Guo Lihua, Hou Lele, Zhao Xiang Aug 2023

Simulation Optimization And Applications Of Pressure-Preserved Triggering Device For Coring In Deep Coal Mines, Shi Xiaojun, Li Minghui, Liu Guikang, You Zhenxi, Guo Lihua, Hou Lele, Zhao Xiang

Coal Geology & Exploration

The pressure-preserved controller is the core component of pressure- and gas-preserved coring equipment used in deep coal mines. Its pressure-preserved capability and sealing performance are the key to pressure- and gas-preserved coring technology. Given that the existing pressure-preserved controller exhibits low initial sealing specific pressure and poor sealing performance when its initial sealing force is provided only by gravity, this study innovatively designed a pressure-preserved triggering device for coring, aiming to provide initial sealing specific pressure required for the sealing of the pressure-preserved controller. Then, this study conducted numerical simulations of the operating process of the triggering device using the …


A Preliminary Study Of Pressure-Preserved Coring Calculation Principle And Method For In-Situ Pressure In Deep Coal Seams, Cui Pengfei, Gao Mingzhong, Shang Delei, Li Jianhua, Chu Peng, Song Jie, Li Yongcheng, Hao Haichun Aug 2023

A Preliminary Study Of Pressure-Preserved Coring Calculation Principle And Method For In-Situ Pressure In Deep Coal Seams, Cui Pengfei, Gao Mingzhong, Shang Delei, Li Jianhua, Chu Peng, Song Jie, Li Yongcheng, Hao Haichun

Coal Geology & Exploration

The accurate acquisition of in-situ gas pressure in coal seams is a key link in the chain of the prevention and control of gas disasters. Presently, it is still necessary to explore accurate, low-cost, and time-saving methods for determining gas pressure. Based on the in-situ pressure-preserved coring for deep coal seams, this study proposed a calculation method for in-situ gas pressure in deep coal seams and developed the calculation process. Using the constructed numerical model of the gas pressure evolution in the pressure-preserved space, this study verified the reliability of the proposed method by comparison with the theoretical and numerical …