Upgrading heavy oil by visbreaking

Abstract

Methods, systems and other embodiments associated with upgrading heavy oil by visbreaking are presented. A method of upgrading heavy oil includes mixing raw heavy oil with flue gases, CO2 and/or steam to produce a mixed heavy oil. This mixture is then heated to produce heated heavy oil. High pressure pulses are created in the heated heavy oil to crack the heated heavy oil to produce cracked oil with a lower viscosity than the heavy oil.

1 . A method of upgrading heavy oil by visbreaking comprising:
 mixing raw heavy oil with at least one of the group of: flue gases, CO2 and steam to produce a mixed heavy oil;   heating the mixed heavy oil to produce heated heavy oil; and   creating high pressure pulses in the heated heavy oil to crack the heated heavy oil to produce cracked oil with a lower viscosity than the heavy oil.   
     
     
         2 . The method of  claim 1  wherein the step of heating the mixed heavy oil further comprises:
 heating the mixed heavy oil in a furnace to about 450 degrees Celsius. 
 
     
     
         3 . The method of  claim 2  further comprising:
 preheating the mixed heavy oil in a preheater to about 375 degrees Celsius prior to the step of heating the mixed heavy oil in the furnace. 
 
     
     
         4 . The method of  claim 1  wherein the step of mixing raw heavy oil is performed in a mixer vessel. 
     
     
         5 . The method of  claim 1  wherein the step of mixing raw heavy oil further comprises:
 creating a vacuum with a venturi, wherein the step of mixing is performed in the venturi. 
 
     
     
         6 . The method of  claim 1  further comprising:
 separating the cracked oil into an overhead stream, a bottoms stream and an upgraded oil stream. 
 
     
     
         7 . The method of  claim 1  further comprising:
 pumping the raw heavy oil at a pressure of about 1500 pounds per square inch (psi); and wherein the step of mixing is performed in a venturi. 
 
     
     
         8 . The method of  claim 1  wherein the step of creating high pressure pulses further comprises:
 creating the high pressure pulses in a cavitation valve. 
 
     
     
         9 . The method of  claim 8 , wherein the step of the creating high pressure pulses is generated by fluid hammering action in the cavitation valve. 
     
     
         10 . The method of  claim 8  wherein the residency time of the heated heavy oil in the cavitation valve is less than three seconds. 
     
     
         11 . The method of  claim 8  wherein the residency time of the heated heavy oil in the cavitation valve is less than one second. 
     
     
         12 . The method of  claim 1  further comprising:
 creating the high pressure pulses that change pressure from about −2000 pounds per square inch gauge (psig) to about 4000 psig, wherein the high pressure pulses have a frequency in a range of 10-100 hertz. 
 
     
     
         13 . A system for upgrading heavy oil by visbreaking comprising:
 a mixer to mix at least one of the group of: flue gases, CO2 and steam with raw heavy oil to produce mixed heavy oil;
 a furnace to heat the mixed heavy oil to create heated heavy oil; and 
   a reaction chamber configured to receive the heated heavy oil and to generate a controlled cavitation with high pressure differentials to facilitate the local cracking of the heated heavy oil to produce cracked oil that has a lower viscosity than the heated heavy oil.   
     
     
         14 . The system of  claim 13 , further comprising:
 a heat exchanger to preheat the mixed heavy oil before it enters the furnace, wherein the cracked oil is circulated through the heat exchanger to preheat the mixed heavy oil.   
     
     
         15 . The system of  claim 13 , further comprising:
 a separator configured to separate the cracked oil into an overhead stream, a bottoms stream and an upgraded oil stream.   
     
     
         16 . The system of  claim 13 , further comprising:
 a heat exchanger to cool the overhead stream to produce a cool overhead stream; and   an overhead separator to separate the cool overhead stream into a non-condensable hydrocarbon gases and a condensate stream.   
     
     
         17 . The system of  claim 13 , wherein the mixer is a venturi that creates a vacuum. 
     
     
         18 . The system of  claim 13  wherein the reaction chamber is a cavitation valve. 
     
     
         19 . The system of  claim 18 , further comprising:
 a piston within the cavitation valve, wherein the high pressure differentials are created, at least in part, by a back-and-forth action of the piston.   
     
     
         20 . The system of  claim 13 , wherein the residency time of the heated heavy oil in the reaction chamber is less than three seconds. 
     
     
         21 . The system of  claim 13 , wherein the residency time of the heated heavy oil in the reaction chamber is less than one second. 
     
     
         22 . The system of  claim 13 , wherein the heater is configured to heat the heavy oil to about 450 degrees Celsius, and wherein the reaction chamber is configured to create pressure differentials between −2000 psig and 4000 psig and between 10 to 100 hertz.