Method for CAGD recovery of heavy oil

Abstract

A novel method for recovering oil is provided wherein oxygen is injected into a chamber within an oil deposit thereby combusting oil at the chamber walls. The heated oil to drains toward the reservoir floor and is recovered via a production well.

1 . A method for producing oil comprising:
 a) providing a steam chamber within an oil formation wherein the steam chamber defines steam chamber walls;   b) injecting oxygen into the steam chamber and initiating combustion of oil at the steam chamber walls;   c) allowing heated and cracked oil to drain toward a production well; and   d) recovering oil through the production well.   
   
   
       2 . The method of  claim 1  wherein the steam chamber is a Steam Assisted Gravity Drainage chamber. 
   
   
       3 . The method of  claim 1  wherein the combustion temperature at the steam chamber wall is higher than the temperature of saturated steam at the steam chamber pressure. 
   
   
       4 . The method of  claim 1  wherein the oxygen concentration in the steam chamber further comprises a means for controlling the combustion temperature. 
   
   
       5 . The method of  claim 1  wherein high purity oxygen is injected in admixture with steam having a quality less than 90%. 
   
   
       6 . The method of  claim 1  wherein the steam chamber walls are maintained at a temperature above that at which oil cracks. 
   
   
       7 . The method of  claim 5  wherein the combustion temperature of an admixture of oxygen and steam is above the saturated steam temperature at the steam chamber pressure. 
   
   
       8 . A method for producing upgraded oil from a heavy oil deposit comprising:
 a) injecting oxygen into an enclosed chamber within the deposit wherein the chamber defines chamber walls;   b) combusting fuel at the chamber walls;   c) maintaining the walls at a combustion temperature higher than the temperature of saturated steam; and   d) withdrawing upgraded oil through a production well.   
   
   
       9 . The method of  claim 8  wherein the oxygen is injected in admixture with steam. 
   
   
       10 . The method of  claim 8  wherein the oxygen is injected in admixture with nitrogen. 
   
   
       11 . The method of  claim 8  wherein the oxygen is supplied as air. 
   
   
       12 . The method of  claim 8  wherein the oxygen is injected above any lower wells.