System for creating a conduit in a borehole formed in an earth formation

Abstract

A system is provided for creating at least one conduit in a borehole formed in an earth formation. The system comprises a device which includes movement means for moving the device in longitudinal direction through the borehole, and injection means for injecting a hardenable substance into the borehole so as to form, for each said conduit, a layer of hardened substance in the borehole behind the device, said layer defining the conduit. The system further comprises control means for controlling the rate of injection of said substance by the injection means so as to correspond with the rate of movement of the device through the borehole by the movement means.

1 . A system for creating at least one conduit in a borehole formed in an earth formation, the system comprising a device which includes: 
 movement means for moving the device in longitudinal direction through the borehole; and    injection means for injecting a hardenable substance into the borehole so as to form, for each said conduit, a layer of hardened substance in the borehole behind the device, said layer defining the conduit; the system further comprising 
 control means for controlling the rate of injection of said substance by the injection means so as to correspond with the rate of movement of the device through the borehole by the movement means.  
   
     
     
         2 . The system of  claim 1 , wherein the injection means is arranged to inject the hardenable substance into the borehole so as to form a cladding of the borehole wall.  
     
     
         3 . The system of  claim 1  or  2 , wherein the injection means includes, for each said conduit, an injection tube extending from the rear end part of the device into the respective conduit in a sealing relationship therewith.  
     
     
         4 . The system of  claim 3 , wherein each injection tube is provided with at least one injection nozzle for injecting said hardenable substance into the borehole, each injection nozzle being arranged a selected distance from the end of the injection tube opposite said rear end part of the device.  
     
     
         5 . The system of  claim 4 , wherein each injection nozzle debouches into an outer annular recess provided at the injection tube.  
     
     
         6 . The system of any one of claims  1 - 5 , further comprising a remote control unit for controlling the device, the remote control unit being in fluid communication with the device via each said conduit.  
     
     
         7 . The system of  claim 6 , wherein the system is suitable to create a first said conduit and a second said conduit, and wherein the system further comprises pumping means for pumping a stream of fluid from the control unit via the first conduit to the device and from the device via the second conduit to the control unit.  
     
     
         8 . The system of  claim 7 , wherein the device is provided with drilling means for deepening the borehole and heat transfer means arranged to transfer heat generated by the drilling means to said stream of fluid.  
     
     
         9 . The system of  claim 8 , wherein the device further includes cuttings transport means for transporting a stream containing drill cuttings generated by the drilling means from the front end part of the device to the rear end part thereof and for depositing the stream containing drill cuttings into the borehole behind the said rear end part.  
     
     
         10 . The system of  claim 9 , wherein the device is provided with a cuttings press arranged to press against a body of drill cuttings formed of drill cuttings deposited behind the rear end part of the device.  
     
     
         11 . The system of  claim 10 , wherein the cuttings press includes a sieve for passage of borehole fluid from the body of drill cuttings into an annular space formed between the device and the borehole wall.  
     
     
         12 . The system of any one of claims  9 - 11 , wherein the cuttings transport means is arranged to selectively induce at least part of the stream containing drill cuttings to flow into the second conduit.  
     
     
         13 . The system of any one of claims  1 - 12 , wherein the injection means includes a first container containing a first compound, a second container containing a second compound and a mixing chamber for mixing the first and second compounds, the hardenable substance being formed from a mixture including said first and second compounds.  
     
     
         14 . The system of  claim 13  when dependent on  claim 7 , wherein the device includes means for selectively transferring the first compound from the first conduit to the first container, and for selectively transferring the second compound from second conduit to the second container.  
     
     
         15 . The system of any of claims  1 - 14 , wherein said device comprises a hydrocarbon fluid inlet for transferring hydrocarbon fluid from the earth formation via said at least one conduit to surface.  
     
     
         16 . The system substantially as described hereinbefore with reference to the accompanying drawings.