Optimizing Heavy Oil Recovery Processes Using Electrostatic Desalters

Abstract

The invention relates to improved bitumen recovery processes and systems. The process may include providing a bitumen froth feed stream, separating the stream in a froth separation unit to produce a diluted bitumen stream, treating the diluted bitumen stream in an electrostatic desalter to produce a treated bitumen stream, and separating the treated bitumen stream into a solvent recycle stream and a bitumen product stream. The system may include a combined AC/DC desalter with a control unit for optimizing the treatment process to produce a product bitumen stream using less solvent and smaller separators than conventional bitumen froth treatment plants and processes.

1 . A method of recovering hydrocarbons, comprising:
 providing a bitumen froth inlet stream including a volume of paraffinic solvents, a volume of water, and asphaltenes;   settling out at least a portion of the asphaltenes in a froth separation unit to produce at least a first settled out asphaltenes stream (a first tailings stream) and a diluted bitumen stream;   separating the volume of paraffinic solvents from the diluted bitumen stream in a solvent recovery unit configured to produce a product bitumen stream and a solvent recycle stream; and   treating at least one of the diluted bitumen stream and the product bitumen stream in at least one electrostatic desalter to produce a treated bitumen stream.   
     
     
         2 . The method of  claim 1 , wherein the electrostatic desalter is configured to remove at least about 10 percent (%) to about 50% of the solids from the at least one of the diluted bitumen stream and the product bitumen stream. 
     
     
         3 . The method of  claim 2 , further comprising settling out at least a portion of the asphaltenes from the first tailings stream in a second froth separation unit configured to receive the first tailings stream and produce at least a second diluted bitumen stream and a second tailings stream containing asphaltenes separated from the first tailings stream. 
     
     
         4 . The method of  claim 3 , wherein the electrostatic desalter is configured to receive at least a portion of the second diluted bitumen stream. 
     
     
         5 . The method of  claim 4 , wherein the electrostatic desalter further comprises:
 an inlet flow conduit operatively connected to a fresh water inlet configured to deliver a fresh water stream to the inlet flow conduit and a chemical inlet configured to deliver a chemical stream to the inlet flow conduit, wherein the inlet flow conduit is configured to deliver the diluted bitumen stream to the electrostatic desalter;   a mixing valve operatively connected to the inlet flow conduit, wherein the mixing valve is configured to impart mixing energy to the diluted bitumen stream and a second stream selected from the group consisting of the fresh water stream, the chemical stream, and any combination thereof; and   an oil outlet configured to produce the treated bitumen stream.   
     
     
         6 . The method of  claim 5 , further comprising:
 receiving at least one data input; and   controlling at least one process condition to configure a composition of the treated bitumen stream based on the at least one data input.   
     
     
         7 . The method of  claim 6 , wherein the at least one data input is selected from the group comprising: a flow rate of the diluted bitumen stream, a flow rate of the fresh water inlet stream, a flow rate of the chemical inlet stream, a composition of the diluted bitumen stream, a composition of chemicals flowing through the chemical inlet, an electrostatic field characteristic, a temperature inside the electrostatic desalter, a mixing valve pressure, a mixing valve intensity, a temperature of the diluted bitumen stream, a thickness of an emulsion layer, and any combination thereof. 
     
     
         8 . The method of  claim 7 , wherein the at least one process condition is selected from the group comprising: the flow rate of the diluted bitumen stream, the flow rate of the fresh water inlet stream, the flow rate of the chemical inlet stream, a solvent content of the diluted bitumen stream, the composition of chemicals flowing through the chemical inlet, the electrostatic field characteristic, the temperature inside the electrostatic desalter, the mixing valve pressure, the mixing valve intensity, the temperature of the diluted bitumen stream, the thickness of an emulsion layer, and any combination thereof. 
     
     
         9 . The method of  claim 4 , further comprising configuring the at least one electrostatic desalter as a plurality of desalting units in a configuration selected from the group consisting of: at least one two-stage train and at least two parallel single-stage units. 
     
     
         10 . The method of  claim 5 , wherein the chemical inlet stream includes a chemical demulsifier.