Method for fluid carriage in deep-seam coal hydraulic mining

Abstract

The present invention relates to a method for fluid carriage in deep-seam coal hydraulic mining, aimed at the mining of coal seams buried underground at depths of 500 metres to below several thousands of metres. By means of methods such as well drilling and tubular columns, hydraulic power is conveyed to the coal seam excavation using tubular columns, to erode and cut coal buried underground, and by circulating fluid at a certain flow rate, cut coal is carried to the surface, achieving unmanned excavation in the shaft. The present method is an integrated coal exploitation technique achieving synchronous mining of coal field gas and solids, and is suitable for coal seams where conventional methods are unable to mine or mining is not economically viable, while also being suitable for establishing gasification channels for underground coal gasification.

1 - 10 . (canceled) 
     
     
         11 . A method for hydraulic mining and fluid carrying of deep-seam coal, for realizing a coal development with integration of synchronous mining of gas and solid of coal fields, for the coal seams which cannot be mined with a conventional method or are uneconomically mined, and for the establishment of gasification tunnels of underground gasification of coal, wherein the method includes:
 by a directional drilling process, using a hydraulic cutting drill and double-layer tubular columns, preparing and using fluid with a certain performance as a carrier, and bringing mixture of underground deep-seam coal out of the ground through the fluid with a flow velocity;   simultaneously separating mud, coal and gas in the mixture by a three-phase separator system; and   coal gas being fed into a gas processing station, then being compressed and transmitted to users;   coal briquettes entering a coal washing workshop and being processed into cleaned coal, which is then transferred to a cleaned coal warehouse for subsequent sale; and   the mud being recycled to a circulation pool for recycling.   
     
     
         12 . The method for hydraulic mining and fluid carrying of deep-seam coal according to  claim 11 , wherein an overall development scheme is drawn up according to the amount of resources from coal resource exploration and the actual situation of the geological formation, and the simultaneous development of a same layer of a single well or multiple wells is implemented according to the overall scheme. 
     
     
         13 . The method for hydraulic mining and fluid carrying of deep-seam coal according to  claim 11 , wherein, several sets of coal seams is developed from deep coal seam to shallow coal seam, and pressure coefficient of coal seams is greater than 0.9. 
     
     
         14 . The method for hydraulic mining and fluid carrying of deep-seam coal according to  claim 12 , wherein, several sets of coal seams is developed from deep coal seam to shallow coal seam, and pressure coefficient of coal seams is greater than 0.9. 
     
     
         15 . The method for hydraulic mining and fluid carrying of deep-seam coal according to  claim 11 , wherein the well drilling process is utilized to establish a production well; after drilling to the top of the deepest coal seam by the well drilling process, a casing is put down for well cementation, and then a cement plug is drilled to open the coal seams. 
     
     
         16 . The method for hydraulic mining and fluid carrying of deep-seam coal according to  claim 11 , wherein the directional drilling process is utilized, a specific hydraulic cutting drill and specific double-layer tubular columns are utilized, fluid with a certain performance is prepared, and finally production is performed by a ground surface mud pump. 
     
     
         17 . The method for hydraulic mining and fluid carrying of deep-seam coal according to  claim 13 , wherein the directional drilling process is utilized, a specific hydraulic cutting drill and specific double-layer tubular columns are utilized, fluid with a certain performance is prepared, and finally production is performed by a ground surface mud pump. 
     
     
         18 . The method for hydraulic mining and fluid carrying of deep-seam coal according to  claim 15 , wherein the directional drilling process is utilized, and a downhole television set, a position finder and a direction instrument are used to ensure the quality of tunneling. 
     
     
         19 . The method for hydraulic mining and fluid carrying of deep-seam coal according to  claim 16 , wherein, hydraulic cutting drills of different parameters are customized according to thicknesses and dip angles of the coal seams, and the parameters include rotation speed, the diameter of nozzles, and the jet angle of nozzles. 
     
     
         20 . The method for hydraulic mining and fluid carrying of deep-seam coal according to  claim 16 , wherein, the double-layer tubular columns of different diameters are utilized according to production capacity, the performance of the fluid is configured according to the pressure coefficient and density of coal seams, and indexes of the performance include density, viscosity and cutting force; the fluid is prepared from water, bentonite, caustic soda, coal powder and gangue powder; and parameters of the mud pump include pressure and displacement. 
     
     
         21 . The method for hydraulic mining and fluid carrying of deep-seam coal according to  claim 11 , wherein the mixture of coal briquettes and coal gas is brought out of the ground through fluid with a certain flow velocity and then enters a processing system on the ground. 
     
     
         22 . The method for hydraulic mining and fluid carrying of deep-seam coal according to  claim 21 , wherein the mixture of the fluid enters a three-phase separation system first so that the mud, coal and gas are separated simultaneously; the coal gas enters a gas processing station, is then compressed and transmitted to users; the coal briquettes enter a coal washing workshop and are then processed into cleaned coal, and the cleaned coal is transferred a cleaned coal warehouse for subsequent sale; ash and gangue from the coal washing workshop enter a gangue grinding plant and are then processed into materials below 200 meshes for preparing mud; waste water from the coal washing workshop is transferred to a mud preparation plant and used for preparing mud; the mud flows into a sedimentation tank from the three-phase separator for settling powdered coal and fine sand particles; and the sediment is transferred to the coal washing workshop for processing, and the mud is recycled to a circulation pool for recycling.