The northern Guizhou coalfield where Xintian Coal Mine is located is located in the northwest of Guizhou. The Longtan Formation of Upper Permian in the area is rich in coalbed methane. The No.4 and No.9 coal seams of ...The northern Guizhou coalfield where Xintian Coal Mine is located is located in the northwest of Guizhou. The Longtan Formation of Upper Permian in the area is rich in coalbed methane. The No.4 and No.9 coal seams of the recoverable coal seams in the whole area are all hard-to-extract coal seams. The gas extraction is difficult and the amount of gas control work is large. In order to effectively contain the occurrence of coal mine gas accidents, improve the gas extraction capacity in Guizhou province and achieve advanced gas control, Xintian Coal Mine and Henan Coalbed Methane Development and Utilization Co., Ltd. have prepared the implementation plan of the "three-zone linkage" gas extraction demonstration project in the upper and lower coal seams of Xintian Coal Mine, and explored the combined gas prevention and control technology in this mine. In the coal mine planning area, a parameter vertical well is constructed by using the method of small bit pressure lifting drilling+air down-the-hole hammer drilling, and the reservoir is reconstructed by using the method of perforation+hydraulic sand addition. An L-shaped horizontal well was constructed by using low-solid polymer drilling fluid and BlackStar EM wireless inclinometer while drilling to track directional drilling. Based on gamma data while drilling, gas logging, cuttings logging and other data, the reservoir was reconstructed by 9-segment cluster perforation fracturing technology with hydraulic pumping bridge plugs. The two wells are drained according to the principle of "continuous, slow, stable and long-term" so as to realize advanced pre-drainage and gas control.展开更多
文摘The northern Guizhou coalfield where Xintian Coal Mine is located is located in the northwest of Guizhou. The Longtan Formation of Upper Permian in the area is rich in coalbed methane. The No.4 and No.9 coal seams of the recoverable coal seams in the whole area are all hard-to-extract coal seams. The gas extraction is difficult and the amount of gas control work is large. In order to effectively contain the occurrence of coal mine gas accidents, improve the gas extraction capacity in Guizhou province and achieve advanced gas control, Xintian Coal Mine and Henan Coalbed Methane Development and Utilization Co., Ltd. have prepared the implementation plan of the "three-zone linkage" gas extraction demonstration project in the upper and lower coal seams of Xintian Coal Mine, and explored the combined gas prevention and control technology in this mine. In the coal mine planning area, a parameter vertical well is constructed by using the method of small bit pressure lifting drilling+air down-the-hole hammer drilling, and the reservoir is reconstructed by using the method of perforation+hydraulic sand addition. An L-shaped horizontal well was constructed by using low-solid polymer drilling fluid and BlackStar EM wireless inclinometer while drilling to track directional drilling. Based on gamma data while drilling, gas logging, cuttings logging and other data, the reservoir was reconstructed by 9-segment cluster perforation fracturing technology with hydraulic pumping bridge plugs. The two wells are drained according to the principle of "continuous, slow, stable and long-term" so as to realize advanced pre-drainage and gas control.
