Method for high temperature steam

Abstract

A method for the recovery of upgraded oil from an oil-bearing formation is provided wherein a hot gas phase fluid comprising steam is brought into contact with a heavy oil reservoir, such as by injection, and the hot fluid heats at least a portion of the reservoir to a temperature high enough for steam cracking, and subsequently the steam is reacted with the heavy oil to produce steam cracked lighter oil.

1 . A method of recovery of upgraded oil from an oil-bearing formation comprising: 
 a) providing a hot gas phase fluid comprising steam;    b) bringing the fluid into contact with a heavy oil reservoir;    c) heating at least a portion of the reservoir to a temperature high enough for steam cracking; and    d) reacting the steam with heavy oil to produce steam cracked lighter oil.    
   
   
       2 . The method of  claim 1  wherein the hot fluid comprises steam produced by a conventional steam flood boiler that is mixed with sufficient oxygen to heat the reservoir to a temperature adequate for steam cracking of oil on combustion.  
   
   
       3 . The method of  claim 1  wherein the hot fluid comprises an admixture of products of downhole combustion and steam.  
   
   
       4 . The method of  claim 1  including the additional step of withdrawing cracked oil through a production well.  
   
   
       5 . The method of  claim 4  wherein the production well is the injection well.  
   
   
       6 . The method of  claim 4  wherein the oil is withdrawn through a horizontal well.  
   
   
       7 . The method of  claim 1  wherein methane and carbon dioxide are produced in addition to steam cracked lighter oil.  
   
   
       8 . The method of  claim 2  wherein said temperature is greater than 900 degrees Fahrenheit.  
   
   
       9 . The method of  claim 1  wherein the hot fluid comprises a catalyst.  
   
   
       10 . The method of  claim 9  wherein the catalyst comprises boria.  
   
   
       11 . The method of  claim 9  wherein the catalyst comprises a potassium compound.  
   
   
       12 . The method of  claim 9  wherein the catalyst comprises a catalytic metal salt.  
   
   
       13 . The method of  claim 7  wherein at least a portion of the methane produced is combusted to produce steam.  
   
   
       14 . The method of  claim 1  wherein the step of bringing the fluid into contact with a heavy oil reservoir comprises injection of the fluid through an injection well.  
   
   
       15 . The method of  claim 14  wherein fluid injection is stopped and oil is subsequently withdrawn through the injection well.  
   
   
       16 . The method of  claim 14  wherein the injection well comprises a horizontal configuration.