Variation of methane adsorption property of coal after the treatment of hydraulic slotting and methane pre-drainage: A case study

Coupled analysis about multi-factors to the effective influence radius of hydraulic flushing: Application of response surface methodology

“…There is an obvious drop in both stress and gas pressure near the borehole; however, the permeability coefficient of coal seam was found to increases substantially following hydraulic flushing and hydraulic slotting. Zou et al (2014) studied the variation in the methane adsorption property of coal after hydraulic slotting and methane predrainage. The results of their studies provide reliable theoretical support for the application of hydraulic slotting.…”

Experimental study of pulsating water pressure propagation in CBM reservoirs during pulse hydraulic fracturing

“…However, ordinary gas drilling is characterized by a small extraction radius, a small flow and fast attenuation due to the low permeability of the coal seam. Many scholars, both in China and abroad, have put forth hydraulic measures to improve coal seam permeability, such as hydraulic fracturing (Huang et al, 2012(Huang et al, , 2014(Huang et al, , 2011Majdi et al, 2012;Wang et al, 2014;Zhang and Chen, 2010), hydraulic flushing (Lu et al, 2010;Wang and Li, 2012), hydraulic slotting (Shen et al, 2012;Zou et al, 2014), etc., which have yielded some positive results. However, with improvements in the level of safety requirements in underground coal mining, these technologies have yielded some negative effects, the most outstanding of which is the high pressure required that increases the number of underground hazards.…”

Research on and Design of a Self-Propelled Nozzle for the Tree-Type Drilling Technique in Underground Coal Mines

“…The surface well drilling method has been widely used in many developed countries, such as the USA, Canada, and Australia. However, the main method in China is underground gas drainage in order to recover gas and coal simultaneously [4][5][6][7].…”