Drilling device

Abstract

The invention relates to a drilling device for hard rock using a fluid, having at least one drill head with a pre-chamber and a mixing chamber where at least one front-facing nozzle and at least one rear-facing nozzle are provided. The fluid is mixed with abrasives in the mixing chamber, and the fluid together with the abrasives exits from the front-facing nozzle or an opening. The fluid flow is separated in the region of the pre-chamber, abrasive-free fluid exits the rear-facing nozzles, abrasives and the abrasive-free fluid are mixed in the mixing chamber, and the fluid mixed with the abrasives exits from the front-pacing nozzle or an opening.

1 - 15 . (canceled) 
     
     
         16 . A drilling device for hard rock with a drilling fluid, the drilling device comprising
 a drill head for being positioned facing said hard rock,   a pre chamber and a mixing chamber being arranged within said drilling head;   at least one distal opening located in said drilling head   at least one rear-facing nozzle provided in said drilling head   wherein said pre chamber is connected to said mixing chamber by a first supply line;   wherein a second supply line is connected to said pre chamber for delivering an abrasive-free fluid   wherein a third supply line is connected to said mixing chamber for delivering an abrasive stream;   wherein said mixing chamber mixes said abrasive stream and said abrasive-free fluid to obtain said drilling fluid;   wherein said at least one distal opening is arranged downstream the mixing chamber; and   wherein said at least one rear-facing nozzle is arranged such that the drilling fluid delivered by said at least one distal opening is repelled by said hard rock being discharged by abrasive-free fluid from said at least one rear-facing nozzle.   
     
     
         17 . The drilling device according to  claim 16 ,
 wherein the pre chamber and the mixing chamber are arranged spatially separated from each other in the drill head.   
     
     
         18 . The drilling device according to  claim 16 ,
 wherein said abrasive-free supply line and said abrasive supply line run inside the drilling device.   
     
     
         19 . The drilling device according to  claim 16 ,
 wherein said at least one abrasive-free supply line runs coaxially to an axis of the drill head.   
     
     
         20 . The drilling device according to  claim 16 ,
 wherein the abrasives reaching the mixing chamber via the abrasive supply line are received from a borehole using a guide plate arranged on the outside of said drill head.   
     
     
         21 . The drilling device according to  claim 16 ,
 wherein the mixing chamber is embodied together with said at least one opening to define an open mixing chamber facing said hard rock.   
     
     
         22 . The drilling device according to  claim 16 ,
 wherein the drill head runs at least partially conical in a direction of said opening.   
     
     
         23 . The drilling device according to  claim 16 , wherein
 the abrasives reaching the mixing chamber via the abrasive supply line are received from a borehole using a guide plate arranged on the outside of said drill head,   the mixing chamber is embodied together with said at least one opening to define an open mixing chamber facing said hard rock, and   the abrasives from the borehole reach the open mixing chamber via said abrasive supply line, wherein said abrasive supply line is radially oriented in said drill head.   
     
     
         24 . The drilling device according to  claim 16 ,
 wherein the rear-facing nozzles are arranged obliquely to a longitudinal center axis of the drill head.   
     
     
         25 . The drilling device according to  claim 16 ,
 wherein the drill head comprises a rotating inner part.   
     
     
         26 . The drilling device according to  claim 25 ,
 wherein the rotating inner part comprises at least one focusing nozzle, and wherein the rotating inner part comprises at least one transition line providing a connection from said abrasive supply line to said mixing chamber.   
     
     
         27 . The drilling device according to  claim 25 ,
 wherein an annular gap is radially provided between a receiving part of the drill head and the rotating inner part.   
     
     
         28 . The drilling device according to  claim 27 ,
 wherein the annular gap has a projected area being larger than a hydraulically effective area of the said annular gap, and   wherein said rotating inner part of said drill head and said abrasive-free fluid provide a hydrodynamical bearing within said annular gap.   
     
     
         29 . The drilling device according to  claim 25 ,
 wherein at least one of a metal strips and a strand-like solid is guided into the drill head via said abrasive supply line, and   wherein the abrasives are produced by the rotating inner part thus cutting said at least one of said metal strips and said stand-like solid into abrasive debris.   
     
     
         30 . Use of the drilling device according to  claim 16  for employing a site selected from a group comprising geothermal reservoirs, oil reservoirs, gas reservoirs, anchor boreholes, exploration boreholes, stimulation boreholes, boreholes for CT drilling and combinations thereof. 
     
     
         31 . A drilling device for hard rock with a drilling fluid, the drilling device comprising
 a drill head for being positioned facing said hard rock, the drill head having a longitudinal axis,   a pre chamber and a mixing chamber being arranged within said drill head;   at least one distal opening located in said drill head; and   at least one rear-facing flushing outlet provided in said drill head;   wherein said pre chamber is connected to said mixing chamber by a first supply line;   wherein a second supply line is connected to said pre chamber for delivering an abrasive-free fluid;   wherein a third supply line is connected to said mixing chamber for delivering an abrasive stream;   wherein said mixing chamber mixes said abrasive stream and said abrasive-free fluid to obtain said drilling fluid;   wherein said at least one distal opening is arranged downstream the mixing chamber; and   wherein said at least one rear-facing flushing outlet traverses the drill head in a direction transverse to said longitudinal axis,   wherein the at least one rear-facing flushing outlet is connected to one of said second supply line and said pre chamber,   such that the drilling fluid delivered by said at least one distal opening and repelled by said hard rock is lead away by abrasive-free fluid discharged from said at least one rear-facing flushing outlet.   
     
     
         32 . A drilling device for hard rock with a drilling fluid, the drilling device comprising
 a drill head for being positioned facing said hard rock,   a pre chamber and a mixing chamber being arranged within said drill head;   at least one distal opening located in said drill head; and   at least one rear-facing flushing outlet provided in said drill head;   wherein said pre chamber is connected to said mixing chamber by a first supply line;   wherein a second supply line is connected to said pre chamber for delivering an abrasive-free fluid;   wherein a third supply line is connected to said mixing chamber for delivering an abrasive stream;   wherein said mixing chamber mixes said abrasive stream and said abrasive-free fluid to obtain said drilling fluid;   wherein said at least one distal opening is arranged downstream the mixing chamber; and   wherein said at least one rear-facing flushing outlet is arranged radially to the said pre chamber,   such that the drilling fluid delivered by said at least one distal opening and repelled by said hard rock is lead away by abrasive-free fluid discharged from said at least one rear-facing flushing outlet.   
     
     
         33 . The drilling device according to  claim 32 ,
 wherein said at least one distal opening is selected from the group comprising an opening, a plurality of openings, a nozzle, a plurality of nozzles, a channel and a plurality of channels.   
     
     
         34 . The drilling device according to  claim 32 ,
 wherein said at least one distal opening is oriented with an acute angle with respect to an axis of said drilling head.   
     
     
         35 . The drilling device according to  claim 32 ,
 wherein said drill head includes a rotatable inner part,   wherein said rotatable inner part is radially supported within said drill head,   wherein the rotatable inner part is arranged downstream said pre chamber, and   wherein the rotatable inner part includes a fluid supply line rotating around a rotational axis of said rotatable part.