5 research outputs found
Mechanism and technical system of ground and underground combined drainage of CBM in âfour region linkageâ in coal mining area
In order to better realize the safe and efficient coordinated development of coal and CBM resources in high gassy mining areas, the four regions (planning region, preparation region, production region and coal mined-out region) linkage ground-underground combined drainage mode (new Jincheng mode) and a series of technical systems of CBM in the whole mining area, all stratum layer and all time were innovatively developed. Relying on the âThirteen Five - Year Planâ national major science and technology projects to continue to tackle key problems, closely combining with the actual production of key coal mining areas in Shanxi Province. This new mode upgraded from the âthree regions linkageâ three-dimensional extraction mode of CBM developed during the âEleventh Five-Yearâ and the âTwelfth Five-Yearâ Plan and it had been widely used in key coal mining areas of Shanxi Province and achieved good results. The ground pre-drainage technology of CBM in the planning area mainly used vertical wells, directional wells, horizontal wells and other technologies in the early stage. But now it had developed into a well factory intensive development mode and technology dominated by multi-fractured horizontal well. After 15 years of ground pre-drainage, the average reduction of No.3 coal seam in East Fifth Panel of Sihe Mine of Jinneng Holding Group had reached 55%. The No.5310 and No.5311 working faces in this panel had successfully completed safe and efficient coal mining, realizing low gas mining in high gas content coal seam. The ground-underground combined drainage technology of CBM in the preparation region made full use of the advantages of the greatly increased permeability in the fracturing affected area and the increased production pressure difference of underground open space drainage. Which formed a three-dimensional drainage network, improved the drainage efficiency, effectively alleviated the tension in the replacement of mining, and promoted high production and efficiency.Based on the characteristics of intense mining activities in the production area and full opening of underground projects, directional drilling rigs were used to accurately complete regional progressive seam drilling, through hole drilling, and high directional long borehole, and accurately and evenly extract the CBM in the production region. This effectively solved the problems of uncontrollable conventional drilling trajectory, easy to form blind areas for drainage, and poor drainage effect, and realized the accurate standard of underground drainage in the production region, ensuring no risk.In view of the problems such as unclear occurrence law of CBM resources in the coal mined-out region, difficulty in resource assessment, and lack of safe drilling and mining technology, the calculation method of CBM resources in the coal mined-out region was created. And a series of technologies for ground drilling and mining in coal mined-out region were developed. 129 wells had been demonstrated and promoted in Shanxi key coal mine areas such as Jincheng, Xishan, Yangquan, etc., 128 million cubic meters of CBM had been pumped and utilized, and 1.92 million tons of carbon dioxide had been reduced.The success of the âfour region linkageâ ground-underground combined drainage mode and a series of technical systems in key coal mining areas of Shanxi had effectively achieved the triple effect of CBM âreducing greenhouse gas emissions, ensuring coal mine safety production, and supplementing green gas energyâ. Which provided strong support for Chinaâs CBM production to increase from 2.58 billion cubic meters in 2006 to 19.17 billion cubic meters in 2020. At the same time, it also provided an effective guarantee for the deepening of coal mining depth year by year in key coal mining areas of Shanxi Province, the increasingly complex mine production conditions, the continuous reduction of the number of production mines, and the steady growth of the total coal output
Grouting solidification technology for fractured soft coal seams and its application in coalbed methane (coal mine gas) extraction
This article presents an effective method for improving the structure and performance of coal rock masses, thereby facilitating coalbed methane extractionâthe grouting solidification technique. A systematic review is conducted on grouting solidification materials, process methods, evaluation techniques, and other related aspects. In conclusion, it is emphasized that the grouting solidification technique requires further refinement in its system, and its continued significance in the dynamically evolving energy and coal industry is underscored. This is crucial for ensuring the efficient development and sustainable utilization of coal and coalbed methane resources