Flow diverter for drilling

Abstract

An apparatus for drilling a borehole in a well is provided. The apparatus comprises a tubular conveyance system; a drilling system connected to one end of the tubular conveyance system and comprising a bottom hole assembly; and a flow diverter positioned in the tubular conveyance system and comprising a first flow channel configured to receive fluid from inside the conveyance system and at least two side flow channels configured to direct fluid from the first flow channel out of the tubular conveyance system. The fluid flow between the first flow channel and each side flow channels is controlled by a valve which is operable to divert fluid out of the tubular conveyance system or to maintain the fluid in the tubular conveyance system.

1 . An apparatus for drilling a borehole in a well, comprising:
 a tubular conveyance system;   a drilling system connected to one end of the tubular conveyance system and comprising a bottom hole assembly; and   a flow diverter positioned in the tubular conveyance system and comprising a first flow channel configured to receive fluid from inside the conveyance system and at least two side flow channels configured to direct fluid from the first flow channel out of the tubular conveyance system;   wherein fluid flow between the first flow channel and each side flow channel is controlled by a valve which is operable to divert fluid out of the tubular conveyance system or to maintain the fluid in the tubular conveyance system.   
     
     
         2 . The apparatus according to  claim 1 , wherein the flow diverter is located in the tubular conveyance system such that, in use, the flow diverter is positioned in the main well. 
     
     
         3 . The apparatus according to  claim 1 , wherein the side flow channels of the flow diverter are arranged to divert flow that has come from inside the drilling system to the annulus above the point at it which the side channels diverts flow from the surface into the annulus. 
     
     
         4 . The apparatus according to  claim 1 , wherein the side flow channels of the flow diverter are arranged to divert flow that has come from the surface to the annulus above the point at which the side channels divert flow that has come from inside the drilling system to the annulus. 
     
     
         5 . The apparatus according to  claim 1 , wherein the valves are controlled by an electrical line from the surface. 
     
     
         6 . The apparatus according to  claim 1 , wherein the valves have a default position such that when a valve actuation signal is lost the valves are configured to return to their default position. 
     
     
         7 . The apparatus according to  claim 1 , wherein the diverter is spoolable. 
     
     
         8 . The apparatus according to  claim 1 , wherein the diameter of the flow diverter is larger than the diameter of the tubular conveyance system. 
     
     
         9 . The apparatus according to  claim 1 , wherein the diameter of the flow diverter is the same as the diameter of the tubular conveyance system. 
     
     
         10 . The apparatus according to  claim 1 , wherein the tubular conveyance system is coiled tubing. 
     
     
         11 . The apparatus according to  claim 1 , further comprising an electric line controlled from the surface running through the diverter and tubular conveyance system to the bottom hole assembly. 
     
     
         12 . The apparatus according to  claim 1 , further comprising a second flow diverter, wherein the second flow diverter forms part of the bottom hole assembly. 
     
     
         13 . The apparatus according to  claim 1 , further comprising a second flow diverter, wherein the second flow diverter is positioned adjacent the bottom hole assembly. 
     
     
         14 . A method for drilling a borehole in an underground formation, comprising the steps of:
 deploying the apparatus according to  claim 1  down a borehole;   pumping a fluid through the tubular conveyance system; and   using the drilling system to drill a borehole.   
     
     
         15 . The method according to  claim 14 , further comprising positioning the apparatus such that the flow diverter is positioned in the main well. 
     
     
         16 . The method according to  claim 14 , further comprising pumping drilling fluid from the surface through the tubular conveyance system. 
     
     
         17 . The method according to  claim 14 , further comprising pumping gas from the surface though the tubular conveyance system to the diverter. 
     
     
         18 . The method according to  claim 14 , further comprising pumping a fluid-gas slurry mixture from the surface through the tubular conveyance system to the diverter. 
     
     
         19 . The method according to  claim 14 , further comprising adjusting the valves of the diverter to direct the received flow from the tubular conveyance system into the annulus. 
     
     
         20 . The method according to  claim 14 , further comprising adjusting the valves of the diverter to maintain the received flow within the tubular conveyance system. 
     
     
         21 . The method according to  claim 14 , further comprising pumping produced well fluids laden with drilling cuttings from the bottom hole assembly to the surface through the diverter. 
     
     
         22 . The method according to  claim 14 , further comprising pumping produced well fluids laden with drilling cuttings to the diverter and into the annulus such that they can be lifted to surface. 
     
     
         23 . The method according to  claim 14 , further comprising pumping drilling fluids laden with drilling cuttings from the bottom hole assembly to surface through the diverter. 
     
     
         24 . The method according to  claim 14 , further comprising pumping drilling fluids laden with drilling cuttings to the diverter and into the annulus such that they can be lifted to surface.