Method and System For Enhancing A Recovery Process Employing One or More Horizontal Wellbores

Abstract

The present invention relates generally to a system and method for enhancing a recovery process employing one or more substantially horizontal wellbores. More particularly, the present invention relates to a method and system for enhancing a recovery process employing one or more horizontal wellbores by providing a zone of increased permeability in a hydrocarbon reservoir to facilitate vertical movement of flowable materials through the reservoir to thereby enhance the recovery process. In some embodiments, the reservoir comprises one or more vertical permeability impediments.

1 . A method of enhancing a hydrocarbon recovery process employing one or more horizontal wellbores, the method comprising:
 providing a zone of increased permeability in a hydrocarbon reservoir to facilitate movement of flowable materials through the reservoir to thereby enhance the recovery process.   
     
     
         2 . The method of  claim 1 , wherein the zone of increased permeability is provided in a region substantially above or below said one or more horizontal wellbores. 
     
     
         3 . The method of  claim 2 , wherein the zone of increased permeability extends generally in a direction substantially parallel the horizontal axis of the one or more horizontal wellbores along at least a portion of the length thereof. 
     
     
         4 . The method of  claim 1 , wherein the zone of increased permeability is provided by an accessory conduit in the reservoir. 
     
     
         5 . The method of  claim 4 , wherein the hydrocarbon reservoir has at least one vertical permeability impediment and the accessory conduit has one or more portions that extend through the at least one vertical permeability impediment. 
     
     
         6 . The method of  claim 1 , wherein the recovery process is a gas recovery process, a conventional oil recovery process or a heavy oil recovery process. 
     
     
         7 . The method of  claim 6 , wherein the heavy oil recovery process is steam-assisted gravity drainage (SAGD), cyclic steam stimulation (CSS), steam flooding or a derivative thereof. 
     
     
         8 . The method of  claim 7 , wherein the heavy oil recovery process is SAGD. 
     
     
         9 . The method of  claim 8 , wherein the one or more horizontal wellbores comprises a production wellbore and an injection wellbore, and wherein the at least one accessory conduit is provided in a region substantially above the injection wellbore. 
     
     
         10 . The method of  claim 9 , wherein the accessory conduit is drilled laterally from an upper hole section of the injection wellbore. 
     
     
         11 . The method of  claim 4 , wherein the at least one vertical permeability impediment is a baffle or a barrier. 
     
     
         12 . A method of enhancing a recovery process employing one or more substantially horizontal wellbores in a hydrocarbon reservoir having at least one vertical permeability impediment, the method comprising:
 providing at least one accessory conduit in a region substantially above or below at least one said one or more substantially horizontal wellbores, the at least one conduit extending generally in a direction substantially parallel to the horizontal plane of the one or more horizontal wellbores along at least a portion of the length thereof.   
     
     
         13 . The method of  claim 12 , wherein the conduit has one or more portions that extend through the vertical permeability impediment to facilitate movement of flowable material therethrough during the recovery process. 
     
     
         14 . The method of  claim 12 , wherein the one or more substantially horizontal wellbores comprises a production well for collection of flowable production material comprising hydrocarbons. 
     
     
         15 . The method of  claim 12 , wherein the one or more substantially horizontal wellbores comprises an injection well for injection of flowable injection material into the reservoir. 
     
     
         16 . The method of  claim 15 , wherein the injection material comprises water, steam, gas, solvent, polymer or a combination thereof to aid in mobilizing hydrocarbons in the reservoir. 
     
     
         17 . The method of  claim 12 , wherein the at least one accessory conduit extends through the at least one vertical permeability impediment along the plane of the vertical permeability impediment. 
     
     
         18 . The method of  claims 12 , wherein the at least one accessory conduit comprises an undulating conduit that crosses one or more said at least one vertical permeability impediment at intervals. 
     
     
         19 . The method of  claim 12 , wherein the at least one accessory conduit comprises a substantially horizontal conduit having a plurality of lateral offshoots that extend through one or more said at least one vertical permeability impediment. 
     
     
         20 . The method of  claim 12 , wherein the at least one accessory conduit comprises a substantially horizontal main conduit having a plurality of perforations extending therefrom that extend through one or more said at least one vertical permeability impediment. 
     
     
         21 . A method of recovering hydrocarbons from a reservoir having at least one vertical permeability impediment, the method comprising:
 providing a production well having a substantially horizontal portion for collection of production material comprising hydrocarbons;   providing an injection well having a substantially horizontal portion for injection of injection material;   providing at least one accessory conduit in the reservoir in a region substantially above or below the production well and/or the injection well and extending generally in a direction parallel to the production well and/or the injection well along at least a portion of its length, the conduit having one or more portions that extend through the vertical permeability impediment to facilitate movement of the production material and/or the injection material through the reservoir; and   recovering the hydrocarbons from the production material.   
     
     
         22 . The method of  claim 21 , wherein the injection material comprises steam, and wherein the at least one accessory conduit creates a zone of increased permeability above the injection well that facilitates the vertical expansion of a steam chamber into one or more upper regions of the reservoir as well as gravity drainage of mobilized heavy oil from the upper regions toward the production well. 
     
     
         23 . A method of increasing permeability of at least one vertical permeability impediment in a reservoir to enhance a hydrocarbon recovery process employing one or more horizontal wellbores, the method comprising:
 providing at least one accessory conduit in the reservoir in a region substantially above or below the one or more horizontal wellbores, the conduit having one or more portions that extend through the at least one vertical permeability impediment to facilitate movement of flowable material therethrough to enhance the recovery process.   
     
     
         24 . A method of enhancing a hydrocarbon recovery process employing one or more horizontal wellbores in a reservoir having at least one vertical permeability impediment, the method comprising:
 increasing the effective permeability of the at least one vertical permeability impediment in a region substantially above or below the one or more horizontal wellbores to facilitate the movement of flowable materials through the at least one vertical permeability impediment to enhance the recovery process.   
     
     
         25 . A method of enhancing recovery process performance in a hydrocarbon reservoir having at least one vertical permeability impediment, comprising:
 providing a first wellbore having a substantially horizontal portion for collection of hydrocarbons; and   providing at least one accessory conduit extending through the reservoir in a region substantially above or below the first wellbore, the accessory conduit having one or more portions that extend through the vertical permeability impediment to facilitate movement of flowable materials therethrough to enhance recovery.   
     
     
         26 . An in situ heavy oil recovery process for recovering hydrocarbons from a reservoir having one or more vertical permeability impediments, comprising:
 providing one or more horizontal wellbores in the reservoir, the one or more horizontal wellbores including a production wellbore; and   increasing the effective permeability of the one or more vertical permeability impediments above the production wellbore in a region extending along at least a portion of the length of the production wellbore to facilitate the movement of flowable materials through the one or more vertical permeability impediments and toward the production wellbore.   
     
     
         27 . A system for recovering hydrocarbons from a reservoir, the system comprising:
 one or more substantially horizontal wellbores, including a production wellbore; and   an accessory conduit located substantially above or below the one or more substantially horizontal wellbores for enhancing vertical movement of flowable materials through the reservoir to thereby enhance recovery.