Sw-sagd with between heel and toe injection

Abstract

The present disclosure relates to a particularly effective well configuration that can be used for single well steam assisted gravity drainage (SW-SAGD), wherein steam injection occurs at one or more points between the heel and toe, instead of at the toe as in the prior art.

1 ) A method of producing heavy oils from a reservoir by single well steam and gravity drainage (SW-SAGD), comprising:
 a) providing a horizontal well below a surface of a reservoir;   b) said horizontal well having a toe end and a heel end and a middle therebetween;   c) injecting steam into one or more injection points between said toe end and said heel end; and   d) simultaneously producing mobilized heavy oil;   e) wherein said method produces more oil at a time point than a similar SW-SAGD well with steam injection only at said toe.   
     
     
         2 ) The method of  claim 1 , wherein each injection point is separated from a production segment by at least two thermal packers. 
     
     
         3 ) The method of  claim 1 , wherein an injection point is at said middle. 
     
     
         4 ) The method of  claim 1 , wherein two injection points are at about ¼ and ¾ of a horizontal length of said well. 
     
     
         5 ) The method of  claim 1 , wherein injected steam includes solvent. 
     
     
         6 ) The method of  claim 1 , wherein said method includes a preheating phase wherein steam is injected along the entire length of the well. 
     
     
         7 ) The method of  claim 1 , wherein said method includes a cyclic preheating phase comprising a steam injection period along the entire length of the well followed by a soaking period. 
     
     
         8 ) The method of  claim 7 , including two cyclic preheating phases. 
     
     
         9 ) The method of  claim 7 , including three cyclic preheating phases. 
     
     
         10 ) The method of  claim 1 , wherein said method includes a pre-heating phase comprising a steam injection in both the injection segment and the production segment followed by a soaking period. 
     
     
         11 ) The method of  claim 10 , including two cyclic pre-heating phases. 
     
     
         12 ) The method of  claim 10 , including three cyclic pre-heating phases. 
     
     
         13 ) The method of  claim 7 , wherein said soaking period is 10-30 days. 
     
     
         14 ) The method of  claim 7 , wherein said soaking period is 20 days. 
     
     
         15 ) A well configuration for producing heavy oils from a reservoir by single well steam and gravity drainage (SW-SAGD), comprising:
 a) a horizontal well in a subsurface reservoir;   b) said horizontal well having a toe end and a heel end and having at least three segments comprising:
 i) at least two production segments bracketing at least one injection segment; 
 ii) said production segments fitted for production; and 
 iii) said injection segments fitted for injection. 
   
     
     
         16 ) The well configuration of  claim 15 , wherein thermal packers separate said injection segments and said production segments. 
     
     
         17 ) The well configuration of  claim 15 , comprising two injection segments bracketed by production segments. 
     
     
         18 ) The well configuration of  claim 16 , wherein said two injection segments are at about ¼ and ¾ of an overall well length. 
     
     
         19 ) The well configuration of  claim 17 , said at least two injection segments fitted with coiled tubing having two orifices to inject steam into said two injection segments. 
     
     
         20 ) The well configuration of  claim 15 , comprising three injection segments bracketed by production segments. 
     
     
         21 ) An improved method of producing heavy oils from a SW-SAGD, wherein steam is injected into a toe end of a horizontal well to mobilize oil which is simultaneously produced at a heel end of said horizontal well, the improvement comprising providing one or more injection points for steam between said heel end and said toe end during a production phase, thus improving a CSOR of said horizontal well at a time period as compared to a similar well with steam injection only at said toe end during said production phase.