Recompaction of Sand Reservoirs

Abstract

Methods and systems for recompacting a hydrocarbon reservoir to prevent override of a fill material are provided. An exemplary method includes detecting a slurry override condition and reducing a pressure within the reservoir so as to reapply a stress from an overburden.

1 . A method for recompacting material in a reservoir, comprising:
 detecting a slurry override condition; and   reducing a pressure within the reservoir so as to reapply a stress from an overburden.   
     
     
         2 . The method of  claim 1 , comprising injecting fluid into the reservoir to increase the pressure to a conditioning pressure. 
     
     
         3 . The method of  claim 1 , wherein reducing the pressure comprises lowering a slurry injection rate while a production rate is maintained constant. 
     
     
         4 . The method of  claim 1 , wherein reducing the pressure comprises lowering a slurry injection rate while increasing a production rate. 
     
     
         5 . The method of  claim 1 , wherein reducing the pressure comprises maintaining a constant slurry injection rate while a production rate is increased. 
     
     
         6 . The method of  claim 1 , wherein reducing the pressure comprises producing substantially only fluid from the reservoir. 
     
     
         7 . The method of  claim 1 , wherein the reservoir is an oil sands formation. 
     
     
         8 . The method of  claim 1 , wherein the reduced pressure is greater than an initial reservoir pressure. 
     
     
         9 . The method of  claim 1 , wherein the reduced pressure is less than a conditioning pressure. 
     
     
         10 . A method for harvesting a hydrocarbon from a sand reservoir, comprising:
 detecting a slurry override condition; and   reducing a pressure within the sand reservoir so as to reapply a stress from an overburden onto the reservoir sand.   
     
     
         11 . The method of  claim 10 , comprising:
 removing at least a portion of a reservoir material from the sand reservoir;   processing the reservoir material to remove at least a portion of associated hydrocarbons and form a clean material;   forming a mixture comprising at least a portion of the clean material; and   reinjecting at least a portion of the mixture into the sand reservoir.   
     
     
         12 . The method of  claim 10 , wherein fluid or slurry are withdrawn from the sand reservoir through injection wells, production wells, or both. 
     
     
         13 . The method of  claim 10 , comprising reducing the pressure within the sand reservoir by allowing fluid to leak-off to a surrounding formation. 
     
     
         14 . The method of  claim 10 , wherein the pressure in the reservoir is raised up to the conditioning pressure once sufficient recompaction has occurred to allow slurry production and slurry injection to be restarted without override. 
     
     
         15 . The method of  claim 10 , wherein the amount of recompaction is sufficient to restart slurry production and slurry injection without override. 
     
     
         16 . The method of  claim 10 , comprising:
 injecting a slurry mixture into the reservoir through a plurality of injection wells; and   producing a reservoir material through a plurality of production wells.   
     
     
         17 . The method of  claim 16 , comprising reducing the pressure within the reservoir by stopping injection of the slurry mixture into at least a portion of the plurality of injection wells. 
     
     
         18 . The method of  claim 16 , comprising reducing the pressure within the reservoir by slowing injection of the slurry mixture into at least a portion of the plurality of injection wells. 
     
     
         19 . The method of  claim 16 , wherein fluid is withdrawn from the reservoir through the plurality of injection wells. 
     
     
         20 . The method of  claim 16 , wherein fluid is withdrawn from the reservoir through one or more production wells while injection of slurry is continued through one or more injection wells. 
     
     
         21 . A system for recompacting a reservoir, comprising:
 an injection well, wherein the injection well is configured to inject a slurry comprising sand and fluid into the reservoir; and   a production well, wherein the production well is configured to produce a slurry comprising sand and hydrocarbon from the reservoir, wherein the injection well, the production well, or both is configured to allow recompaction of the reservoir.   
     
     
         22 . The system of  claim 21 , wherein the injection well, the production well, or both comprise at least a segment comprising a sand filter configured to filter sand from a produced fluid. 
     
     
         23 . The system of  claim 21 , wherein the injection well is configured to allow the production of fluid substantially free of entrained sand from the reservoir. 
     
     
         24 . The system of  claim 21 , wherein the production well is configured to allow the production of fluid substantially free of entrained sand from the reservoir.