Producing hydrocarbon fluid from a layer of oil sand

Abstract

A method of producing hydrocarbons from a layer of oil sand located in a formation comprises creating a plurality of boreholes in the formation, including a first borehole and a second borehole spaced from the first borehole in a selected direction along which the layer of oil sand extends, and creating a cavity in the layer, the cavity being in fluid communication with the first borehole; extending the cavity in the selected direction by operating fluid jetting means via the first borehole to jet a stream of fluid against the cavity wall; when the cavity is in fluid communication with the second borehole, operating the fluid jetting means via the second borehole to jet a stream of fluid against the cavity wall so as to further extend the cavity; and transporting a slurry of fluid and oil sand from the cavity to a processing facility.

1 . A method of producing hydrocarbon fluid from a layer of oil sand located in an earth formation, the method comprising:
 creating a plurality of boreholes in the earth formation, including a first injection borehole and a second injection borehole spaced from the first injection borehole in a selected direction along which the layer of oil sand extends, and creating a cavity in the layer of oil sand, the cavity being in fluid communication with the first injection borehole;   extending the cavity in the selected direction by operating fluid jetting means via the first injection borehole to jet a stream of fluid against a wall of the cavity;   when the cavity is in fluid communication with the second injection borehole, operating the fluid jetting means via the second injection borehole to jet a stream of fluid against the wall of the cavity so as to further extend the cavity; and   transporting a slurry of fluid and oil sand, resulting from operation of the fluid jetting means, from the cavity via a discharge borehole to a processing facility for processing the slurry, the discharge borehole having a lower section extending in the selected direction and being in fluid communication with the cavity at said wall of the cavity.   
     
     
         2 . The method of  claim 1 , wherein the step of operating the fluid jetting means via the second injection borehole comprises removing the fluid jetting means from the first injection borehole and inserting the fluid jetting means into the second injection borehole. 
     
     
         3 . The method of  claim 1 , wherein the second injection borehole is created after creating the first injection borehole, in correspondence with extension of the cavity in the selected direction. 
     
     
         4 . The method of  claim 1  wherein the method further comprises inserting a stream of refill material into the cavity via the first injection borehole. 
     
     
         5 . The method of  claim 4 , wherein the stream of refill material comprises sand. 
     
     
         6 . The method of  claim 4  wherein the stream of refill material is transported from the processing facility to the cavity. 
     
     
         7 . The method of  claim 1  wherein the lower section of the discharge borehole is provided with a liner adapted to be changed in length, and wherein the method further comprises changing the length of the liner in correspondence with extension of the cavity in the selected direction. 
     
     
         8 . The method of  claim 7 , wherein the liner is adapted to be shortened, and wherein the step of changing the length of the liner comprises shortening the liner in correspondence with extension of the cavity in the selected direction. 
     
     
         9 . The method of  claim 8 , wherein shortening the liner comprises operating a cutting device to cut the liner, preferably wherein the liner is made of a non-metal material, more preferably of a plastics material. 
     
     
         10 . The method of  claim 1 , wherein the discharge borehole is provided with pumping means for pumping the slurry via the discharge borehole to the processing facility. 
     
     
         11 . The method of  claim 10 , wherein the pumping means includes a pump sealed relative to an inner surface of the liner. 
     
     
         12 . The method of  claim 10 , wherein the pumping means is axially movable through the discharge borehole, and wherein the method further comprises axially moving the pumping means through the discharge borehole in correspondence with changing the length of the liner. 
     
     
         13 . The method of  claim 1  wherein the pumping means is driven by a stream of fluid pumped through a conduit extending through the discharge borehole. 
     
     
         14 . The method of  claim 13 , wherein at least a portion of said stream of fluid is injected into the slurry of fluid and oil sand present in the cavity. 
     
     
         15 . (canceled)