Method for extracting bitumen from an aged oil sands ore stream

Abstract

The present invention provides a method for extracting bitumen from an aged oil sands ore stream, the method comprising at least the steps of: (a) providing an aged oil sands ore stream, the oil sands ore stream containing connate water; (b) contacting the aged oil sands ore stream with a solvent thereby obtaining a solvent-diluted oil sand slurry; (c) filtering the solvent-diluted oil sand slurry obtained in step (b), thereby obtaining a solids-depleted stream and a solids-enriched stream; (d) removing solvent from the solids-depleted stream obtained in step (c) thereby obtaining a bitumen-enriched stream; wherein the solvent as used in step (b) comprises a non-aqueous solvent; and wherein the connate water in the aged oil sands ore stream as provided in step (a) has a sulphate concentration of at least 50 ppmv, as determined by ASTM D516.

We claim: 
     
         1 . A method for extracting bitumen from an aged oil sands ore stream, the method comprising at least the steps of:
 (a) providing an aged oil sands ore stream, the oil sands ore stream containing connate water;   (b) contacting the aged oil sands ore stream with a solvent thereby obtaining a solvent-diluted oil sand slurry;   (c) filtering the solvent-diluted oil sand slurry obtained in step (b), thereby obtaining a solids-depleted stream and a solids-enriched stream;   (d) removing solvent from the solids-depleted stream obtained in step (c) thereby obtaining a bitumen-enriched stream;
 wherein the solvent as used in step (b) comprises a non-aqueous solvent; and 
 wherein the connate water in the aged oil sands ore stream as provided in step (a) has a sulphate concentration of at least 50 ppmv, as determined by ASTM D516. 
   
     
     
         2 . The method according to  claim 1 , wherein the connate water in the aged oil sands ore stream as provided in step (a) has a sulphate concentration of at least 80 ppmv, preferably at least 100 ppmv, as determined by ASTM D516. 
     
     
         3 . The method according to  claim 1 , wherein the connate water in the aged oil sands ore stream as provided in step (a) has a magnesium concentration of at least 3.0 ppmv, preferably at least 4.0 ppmv, more preferably at least 5.0 ppmv, as determined by ASTM D511. 
     
     
         4 . The method according to  claim 1 , wherein the connate water in the aged oil sands ore stream as provided in step (a) has a calcium concentration of at least 4.0 ppmv, preferably at least 5.0 ppmv, more preferably at least 10.0 ppmv, as determined by ASTM D511. 
     
     
         5 . The method according to  claim 1 , wherein the connate water in the aged oil sands ore stream as provided in step (a) has a pH of at most 7.5, as determined by ASTM D1293. 
     
     
         6 . The method according to  claim 1 , wherein the aged oil sands ore stream as provided in step (a) has a moisture content of at most 3.0 wt. %, based on the oil sands ore stream, preferably at most 2.5 wt. %, more preferably at most 2.0 wt. % even more preferably at most 1.8 wt. %.