Variable rate steam injection, including via solar power for enhanced oil recovery, and associated systems and methods

Abstract

Systems and methods for variable rate steam injection, including via solar power for enhanced oil recovery, are disclosed. Several embodiments include using the variable nature of solar-generated steam to improve the efficiency and cost-effectiveness of enhanced oil recovery processes. In particular embodiments, the variable rate injection can provide more uniform steam distribution in an oil-bearing formation, at a lower cost than if the same amount of steam were provided on a continuous basis.

1 - 75 . (canceled) 
     
     
         76 . A method for enhanced oil recovery, comprising:
 directing a first quantity of solar-heated steam into an oil-bearing formation via a first set of injection sites during a first period of time, wherein an average incident solar radiation level during the first period has a first value;   directing a second quantity of solar-heated steam into the oil-bearing formation via a second set of injection sites during a second period of time, wherein:
 an average incident solar radiation level during the second period has a second value less than first value; 
 the second quantity of steam is less than the first quantity of steam; and 
 the second set of injection sites has fewer injection sites than the first set of injection sites. 
   
     
     
         77 . The method of  claim 76  wherein the first period of time is primarily during the summer. 
     
     
         78 . The method of  claim 76  wherein the first period of time is primarily daylight hours and the second period of time is primarily night-time hours. 
     
     
         79 . The method of  claim 76  wherein the first period of time is a first set of days and the second period of time is a second set of days. 
     
     
         80 . The method of  claim 76 , further comprising removing oil from the oil-bearing formation after injecting at least one of the first and second quantities of solar-heated steam. 
     
     
         81 . The method of  claim 76  wherein the second set of injection sites includes injection sites that are not part of the first set of injection sites. 
     
     
         82 . The method of  claim 76  wherein the first set of injection sites includes injection sites that are not part of the second set of injection sites. 
     
     
         83 . The method of  claim 76 , further comprising supplementing the solar-heated steam with non-solar-heated steam during the first period of time, the second period of time, or both. 
     
     
         84 . An enhanced oil recovery system, comprising:
 a controller programmed with instructions that, when executed, control oil extraction from an oil-bearing formation by:
 directing a first quantity of solar-heated steam into an oil-bearing formation via a first set of injection sites during a first period of time, wherein an average incident solar radiation level during the first period has a first value; 
 directing a second quantity of solar-heated steam into the oil-bearing formation via a second set of injection sites during a second period of time, wherein: 
 an average incident solar radiation level during the second period has a second value less than first value; 
 the second quantity of steam is less than the first quantity of steam; and 
 the second set of injection sites has fewer injection sites than the first set of injection sites. 
   
     
     
         85 . The system of  claim 84  wherein the first period of time is primarily during the summer. 
     
     
         86 . The system of  claim 84  wherein the first period of time is primarily daylight hours and the second period of time is primarily night-time hours. 
     
     
         87 . The system of  claim 84  wherein the first period of time is a first set of days and the second period of time is a second set of days. 
     
     
         88 . The system of  claim 84  wherein the second set of injection sites includes injection sites that are not part of the first set of injection sites. 
     
     
         89 . The method of  claim 84  wherein the first set of injection sites includes injection sites that are not part of the second set of injection sites. 
     
     
         90 - 104 . (canceled)