Extended reach steam assisted gravity drainage with oxygen ("ersagdox")

Abstract

A process to recover hydrocarbons from a reservoir, where the hydrocarbons have an initial viscosity greater than 100,000 cp, preferably greater than 1,000 cp, the process including: (a) Initially injecting oxygen into the reservoir; (b) Allowing for combustion of the oxygen to vaporize connate water in the hydrocarbon reservoir; (c) Collecting hydrocarbons in a substantially horizontal production well in the reservoir and where the substantially horizontal production well has a length greater than about 800 metres.

1 . A process to recover hydrocarbons from a reservoir, where said hydrocarbons have an initial viscosity greater than 100,000 cp, said process comprising:
 (a) Initially injecting oxygen into said reservoir;   (b) Allowing for combustion of said oxygen to vaporize connate water in said hydrocarbon reservoir;   (c) Collecting hydrocarbons in a substantially horizontal production well in said reservoir and where said substantially horizontal production well has a length greater than about 800 metres.   
     
     
         2 . A process according to  claim 1  further comprising initial steam injection into the reservoir then terminating said steam injection. 
     
     
         3 . A process according to  claim 2  where the ratio of oxygen to steam injected is controlled in the range from 0.05 to 1.00 (v/v). 
     
     
         4 . A steam assisted gravity drainage with oxygen system for recovery of hydrocarbons from a reservoir, where said hydrocarbons have an initial viscosity greater than 100,000 cp, said system comprising:
 (a) A first well for capturing said hydrocarbons, having a toe and a heel and a length greater than about 800 metres, said first well being substantially horizontal and at a first depth;   (b) A second well within said hydrocarbon containing reservoir, having a length greater than about 800 metres, for injection of oxygen into said hydrocarbon containing reservoir, being at second depth said second depth shallower than said first depth;   (c) Said second well being located proximate said toe of said first well; and   (d) A vent gas means for venting any gas produced in said reservoir.   
     
     
         5 . A system according to  claim 4  where said vent gas means is single or multiple vertical wells. 
     
     
         6 . A system according to  claim 4  where said vent gas means is a segregated annulus section in the heel rise section of the substantially horizontal well. 
     
     
         7 . A steam assisted gravity drainage with oxygen system for recovery of hydrocarbons from a reservoir, where said hydrocarbons have an initial viscosity greater than 100,000 cp, said system comprising:
 (a) A first well, having a toe and a heel and a length greater than about 800 metres, said first well within said hydrocarbon containing reservoir, for capturing said hydrocarbons;   (b) A second well within said hydrocarbon containing reservoir, having a length greater than about 800 metres, for injection of oxygen and steam into said hydrocarbon containing reservoir;   (c) Said second well being located proximate said toe of said first well; and   (d) At least one vent gas means for venting any gas produced in said reservoir.   
     
     
         8 . A system according to  claim 7  where said at least one vent gas means is single or multiple vertical wells. 
     
     
         9 . A system according to  claim 7  where said at least one vent gas means is a segregated annulus section in the heel rise section of the substantially horizontal well. 
     
     
         10 . A system according to  claim 7  where said second well is single or multiple vertical wells used for said injection of oxygen and steam. 
     
     
         11 . A system according to  claim 10  where said steam and oxygen are comingled on the surface prior to injection. 
     
     
         12 . A system according to  claim 10  where said steam and oxygen are segregated using packers and injected separately into said single or multiple vertical wells. 
     
     
         13 . A system according to  claim 12  where said steam and oxygen are segregated using concentric tubing and packers, with steam in the central tubing surrounded by oxygen in the adjacent annulus, with said oxygen injected at a higher elevation in the reservoir than said steam. 
     
     
         14 . A steam assisted gravity drainage with oxygen system for recovery of hydrocarbons for a reservoir, where said hydrocarbons have an initial viscosity greater than 100,000 cp, said system comprising:
 (a) A substantially horizontal well, having a toe and a heel and a length greater than 800 metres, said well being located within said hydrocarbon containing reservoir; wherein said well further comprises:   (b) At least one oxygen injection site proximate said toe, for injecting oxygen into said reservoir;   (c) A hydrocarbon recovery site for recovery of said hydrocarbons from said reservoir; and   (d) At least one vent gas site for venting any gas produced in said reservoir.   
     
     
         15 . A system according to  claim 14  where said oxygen injection site is a segregated toe section of said substantially horizontal well. 
     
     
         16 . A steam assisted gravity drainage with oxygen system for recovery of hydrocarbons for a reservoir, where said hydrocarbons have an initial viscosity greater than 100,000 cp, said system comprising:
 (a) A substantially horizontal well, having a toe and a heel and a length greater than 800 metres, said well being located within said hydrocarbon containing reservoir; wherein said well further comprises:   (b) At least one oxygen injection site proximate said toe, for injecting oxygen into said reservoir;   (c) At least one steam injection site, for injecting steam into said reservoir;   (d) A hydrocarbon recovery site for recovery of said hydrocarbons from said reservoir; and   (e) At least one vent gas site for venting any gas produced in said reservoir.   
     
     
         17 . A system according to  claim 16  where said oxygen and steam injection site is a segregated toe section of said substantially horizontal well. 
     
     
         18 . The process according to  claim 1  wherein said hydrocarbons have an initial viscosity range greater than 1,000 cp. 
     
     
         19 . The system according to  claim 4  wherein said hydrocarbons have an initial viscosity range greater than 1,000 cp. 
     
     
         20 . The system according to  claim 7  wherein said hydrocarbons have an initial viscosity range greater than 1,000 cp.