Relocatable Systems and Processes for Recovery of Bitumen From Oil Sands

Abstract

Relocatable systems and processes for processing oil sands are described. Relocatable components are employed to permit oil sand processing to be conducted near a mine face, and relocated as the mine face recedes. Flow of the slurry in combination with appropriate water injection through the relocatable pipeline causes agglomeration of fines within the slurry. Bitumen/solvent mixtures can be filtered from the agglomerates within downstream solvent extraction system components. A high quality bitumen product is formed, having water and solids content that exceeds downstream processing and pipeline requirements. Dry tailings may be back-filled in-pit.

1 . A relocatable system for processing oil sands, the system comprising:
 a relocatable slurry system having an organic solvent inlet therein, and being relocatable to a near mine face location, for receiving oil sands from the mine and for mixing the oil sands therein with a solvent to form a slurry; and   a relocatable pipeline in fluid communication with the relocatable slurry system having a water or high fines stream inlet therein, for receiving the slurry from the relocatable slurry system, for receiving water or high fines streams from a water-based extraction process for mixing with the slurry, and for transporting the slurry while agglomerating solids within the slurry through turbulent flow through the pipeline, for delivery of an agglomerated slurry to downstream solvent extraction components.   
     
     
         2 . The system of  claim 1 , additionally comprising a relocatable crushing unit, relocatable to a location between the mine face and the relocatable slurry system, for receiving and crushing oil sands ore and for providing oil sands to the relocatable slurry system. 
     
     
         3 . The system of  claim 2 , wherein a conveyor is used to convey crushed oil sands ore from the relocatable crushing unit to the relocatable slurry system. 
     
     
         4 . The system of  claim 1 , additionally comprising a relocatable solids content reducing unit for reducing the solids content of the oil sands prior to entry of oil sands into the relocatable slurry system. 
     
     
         5 . The system of  claim 4 , wherein the relocatable solids content reducing unit comprises one of a desanding unit and a relocatable flotation unit. 
     
     
         6 . (canceled) 
     
     
         7 . The system of  claim 1 , additionally comprising downstream solvent extraction components for extraction of the agglomerated slurry with the organic solvent. 
     
     
         8 . The system of  claim 7 , wherein the downstream solvent extraction components comprise a solid-liquid separator for separating agglomerates from the agglomerated slurry, and a tailings solvent recovery unit. 
     
     
         9 . The system of  claim 7 , wherein the downstream solvent extraction components comprise:
 a primary solid-liquid separator for separating the agglomerated slurry into agglomerates and a low solids bitumen extract;   a gravity separator for receiving the low solids bitumen extract and a second solvent; and   a primary solvent recovery unit for recovering solvent from a high grade bitumen extract arising from the gravity separator and for separating bitumen therefrom.   
     
     
         10 . The system of  claim 8 , wherein the solid-liquid separator comprises a belt filter for washing of agglomerates with progressively cleaner solvent. 
     
     
         11 . The system of  claim 8 , additionally comprising clean solvent storage for storing clean solvent derived from the tailings solvent recovery unit. 
     
     
         12 . The system of  claim 8 , additionally comprising a relocatable conveyor system or a relocatable stacker to back-fill dry tailings in-pit. 
     
     
         13 . The system of  claim 9 , wherein the primary solid-liquid separator comprises a gravity separator, cyclone, screen, or belt filter. 
     
     
         14 . (canceled) 
     
     
         15 . The system of  claim 13 , additionally comprising a secondary solid-liquid separator comprising a gravity separator, cyclone, screen, or belt filter. 
     
     
         16 . The system of  claim 9 , additionally comprising a secondary solvent recovery unit for recovering solvent from the agglomerates separated in the primary solid-liquid separator. 
     
     
         17 . The system of  claim 16 , wherein the secondary solvent recovery unit comprises a distillation unit or a flash drum. 
     
     
         18 . A process for forming an agglomerated slurry from oil sands comprising:
 receiving oil sands in a relocatable slurry system located at a near mine face location;   mixing oil sands with a first solvent within the relocatable slurry system to form an initial slurry; and   pumping the slurry through a relocatable pipeline, with subsequent injection of water or high fines streams from a water-based extraction process, to downstream solvent extraction,   wherein turbulent flow through the pipeline causes agglomeration of solids within the initial slurry, forming an agglomerated slurry.   
     
     
         19 . The process of  claim 18 , additionally comprising crushing oil sands ore in a relocatable crushing unit located between the mine face and the relocatable slurry system, and conveying crushed ore to the relocatable slurry system. 
     
     
         20 . The process of  claim 18 , additionally comprising reducing the solids content of the oil sands prior to receiving oil sands in the relocatable slurry system. 
     
     
         21 . The process of  claim 20 , wherein reducing the solids content comprises partial desanding of oil sand in a relocatable desanding unit prior to receiving oil sands in the relocatable slurry system. 
     
     
         22 . The process of  claim 20 , wherein reducing solids comprises floatation in a relocatable floatation unit. 
     
     
         23 . A process for obtaining a bitumen product from oil sands comprising:
 forming an agglomerated slurry according to the process of  claim 18 ; and   subjecting the agglomerated slurry to solvent extraction to form a bitumen product.   
     
     
         24 . The process of  claim 23  wherein solvent extraction comprises:
 removing agglomerates from the agglomerated slurry to form a low solids bitumen extract; 
 mixing a second solvent with the low solids bitumen extract to form a solvent-bitumen low solids mixture, the second solvent having a similar or lower boiling point than the first solvent; 
 subjecting the mixture to gravity separation to produce a high grade bitumen extract and a low grade bitumen extract; and 
 recovering the first and second solvent from the high grade bitumen extract, leaving a high grade bitumen product. 
 
     
     
         25 . The process of  claim 23  wherein solvent extraction comprises:
 mixing a second solvent with the agglomerated slurry to form a solvent-bitumen agglomerated slurry mixture, the second solvent having a similar or lower boiling point than the first solvent; 
 subjecting the mixture to separation to produce a high grade bitumen extract and a low grade bitumen extract; 
 recovering the first and second solvent from the high grade bitumen extract, leaving a high grade bitumen product; and 
 recovering the first and second solvent from the low grade bitumen extract, leaving a low grade bitumen product. 
 
     
     
         26 . The process of  claim 24 , wherein the ratio of first solvent to bitumen in the initial slurry is selected to avoid precipitation of asphaltenes during agglomeration. 
     
     
         27 . The process of  claim 26 , wherein the ratio of the first solvent to bitumen in the initial slurry is less than 2:1, and is selected to limit precipitation of asphaltenes during agglomeration. 
     
     
         28 . The process of  claim 24 , wherein the initial slurry is formed in a low oxygen environment under a gas blanket. 
     
     
         29 . The process of  claim 24 , wherein the first solvent comprises a paraffinic solvent, a cyclic aliphatic hydrocarbon, or a mixture thereof. 
     
     
         30 . The process of  claim 29  wherein the paraffinic solvent comprises an alkane, a natural gas condensate, a distillate from a fractionation unit, or a combination thereof containing more than 40% small chain paraffins of 5 to 10 carbon atoms. 
     
     
         31 . The process of  claim 24 , wherein the second solvent comprises a low boiling point alkane or an alcohol having a boiling point of less than 100° C. 
     
     
         32 . The process of  claim 24 , wherein the first solvent and the second solvent are the same.