Method of producing hydrocarbon fluid from a layer of oil sand

Abstract

A method of producing hydrocarbon fluid from a layer of oil sand located in an earth formation, the method comprising creating at least one borehole in the earth formation, including a discharge borehole having a borehole section extending in a selected direction at an angle of less than 45 degrees with an upper and/or lower boundary of the layer and being provided with a liner of a length adapted to be changed, and creating a cavity in the layer of oil sand, the cavity being in fluid communication with said borehole section; extending the cavity in the selected direction by operating fluid jetting means via said at least one borehole to jet a stream of fluid against a wall of the cavity; changing the length of the liner in correspondence with extension of the cavity in the selected direction; and transporting a slurry of fluid and oil sand, resulting from operation of the fluid jetting means, from the cavity via the discharge borehole to a processing facility for processing the slurry.

1 . A method of producing hydrocarbon fluid from a layer of oil sand located in an earth formation, the method comprising:
 creating at least one borehole in the earth formation, including a discharge borehole having a borehole section extending in a selected direction at an angle of less than 45 degrees with an upper and/or lower boundary of the layer and being provided with a liner of a length adapted to be changed, and creating a cavity in the layer of oil sand, the cavity being in fluid communication with said borehole section;   extending the cavity in the selected direction by operating fluid jetting means via said at least one borehole to jet a stream of fluid against a wall of the cavity;   changing the length of the liner in correspondence with extension of the cavity in the selected direction; and   transporting a slurry of fluid and oil sand, resulting from operation of the fluid jetting means, from the cavity via the discharge borehole to a processing facility for processing the slurry.   
     
     
         2 . The method of  claim 1 , 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. 
     
     
         3 . The method of  claim 2 , 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. 
     
     
         4 . The method of  claim 1  wherein the discharge borehole is provided with a pump for pumping the slurry via the discharge borehole to the processing facility. 
     
     
         5 . The method of  claim 4 , wherein the pump is axially movable through the discharge borehole, and wherein the method further comprises axially moving the pump through the discharge borehole in correspondence with changing the length of the liner. 
     
     
         6 . The method of  claim 1  wherein the pump is driven by a stream of fluid pumped through a conduit extending through the discharge borehole, and wherein at least a portion of said stream of fluid is injected into the slurry of fluid and oil sand present in the cavity. 
     
     
         7 . The method of  claim 1  wherein the selected direction is substantially parallel with an upper and/or lower boundary of the layer. 
     
     
         8 . The method of  claim 1  wherein said at least one borehole further includes an injection borehole separate from the discharge borehole, via which injection borehole the fluid jetting means is operated. 
     
     
         9 . The method of  claim 1  wherein said at least one borehole includes a first injection borehole in fluid communication with the cavity and a second injection borehole spaced from the first injection borehole in the selected direction, and wherein the step of extending the cavity in the selected direction comprises operating the fluid jetting means via the first injection borehole to jet a stream of fluid against said wall of the cavity and, 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. 
     
     
         10 . The method of  claim 9 , wherein the step of extending the cavity in the selected direction comprises removing the fluid jetting means from the first injection borehole and inserting the fluid jetting means into the second injection borehole. 
     
     
         11 . The method of  claim 9  wherein the second injection borehole is created after creating the first injection borehole, in correspondence with extension of the cavity in the selected direction. 
     
     
         12 . The method of  claim 9  wherein the method further comprises inserting a stream of refill material into the cavity via the first injection borehole. 
     
     
         13 . The method of  claim 12 , wherein the stream of refill material comprises sand. 
     
     
         14 . The method of  claim 12  wherein the stream of refill material is transported from the processing facility to the cavity. 
     
     
         15 . The method of  claim 1  wherein said borehole section of the discharge borehole extends substantially horizontally in the selected direction.