Based on the production data of a large number of surface drainage wells in the Huainan mining area,the present study shows that four types of typical production characteristics for relieved methane wells are recogniz...Based on the production data of a large number of surface drainage wells in the Huainan mining area,the present study shows that four types of typical production characteristics for relieved methane wells are recognized,of which the stable type for production and gas concentration is the most dominate,as determined by a comprehensive study on the volume and concentration of drained gases, as well as the stress changes of rocks influenced by mining.Some influence factors for the productive differences of the drainage wells were also been discussed.The results indicate that protective coal-seam mining has a significant effect on overlying strata,which promotes the development of pores and fractures of coal reservoirs for methane desorption and migration;however,the production and the stability of drainage wells are affected by deformation and damage of the overlying strata.The second distribution of strata stress is caused by mining engineering,and if the stress load is larger than the carrying capacity of the extraction well,the gas production would be influenced by the drainage well that has been damaged by rock movement.Furthermore,the case damage occurs first in the weak, lithologic interface by its special mechanical properties.The stability of drainage wells and the production status are also influenced by the different drilling techniques,uneven distribution of gas concentration,and combination of gob gas and methane from the protected layer.展开更多
The importance of simultaneous coal and methane extraction and its significance on green exploitation is stated, and current research situation of simultaneous coal and methane and faced new problems are introduced. T...The importance of simultaneous coal and methane extraction and its significance on green exploitation is stated, and current research situation of simultaneous coal and methane and faced new problems are introduced. The research progress on movement of overlying strata and stresses change in them, cracks development during mining in overlying strata and meth- ane emission under disturbance of mining as well as the changing rules of permeability and methane flow under the disturbance of mining is analyzed. The progress on practice of simultaneous coal and methane extraction is analyzed. The deficiencies of current research and further researching fields on simultaneous coal and methane extraction are pointed out.展开更多
基金supported by the National High Technology Research and Development Program of China (863)(grant no.2007AA06Z220)Important Project of the Ministry of Education(grant no.307014)the Huainan Mining Group program
文摘Based on the production data of a large number of surface drainage wells in the Huainan mining area,the present study shows that four types of typical production characteristics for relieved methane wells are recognized,of which the stable type for production and gas concentration is the most dominate,as determined by a comprehensive study on the volume and concentration of drained gases, as well as the stress changes of rocks influenced by mining.Some influence factors for the productive differences of the drainage wells were also been discussed.The results indicate that protective coal-seam mining has a significant effect on overlying strata,which promotes the development of pores and fractures of coal reservoirs for methane desorption and migration;however,the production and the stability of drainage wells are affected by deformation and damage of the overlying strata.The second distribution of strata stress is caused by mining engineering,and if the stress load is larger than the carrying capacity of the extraction well,the gas production would be influenced by the drainage well that has been damaged by rock movement.Furthermore,the case damage occurs first in the weak, lithologic interface by its special mechanical properties.The stability of drainage wells and the production status are also influenced by the different drilling techniques,uneven distribution of gas concentration,and combination of gob gas and methane from the protected layer.
基金Supported by the National Science Foundation of China （51304006） the Key Project of Anhui Provincial Department of Education （KJ2011A075） the Youth Backbone Training Funds of Anhui University of Science ＆Technology （20120012）
文摘The importance of simultaneous coal and methane extraction and its significance on green exploitation is stated, and current research situation of simultaneous coal and methane and faced new problems are introduced. The research progress on movement of overlying strata and stresses change in them, cracks development during mining in overlying strata and meth- ane emission under disturbance of mining as well as the changing rules of permeability and methane flow under the disturbance of mining is analyzed. The progress on practice of simultaneous coal and methane extraction is analyzed. The deficiencies of current research and further researching fields on simultaneous coal and methane extraction are pointed out.
