Pressure swing processes for producing heavy hydrocarbons from reservoir

Abstract

A process for producing hydrocarbon material from a hydrocarbon reservoir through a production well that is disposed in fluid communication with an injection well via an interwell region disposed within a communication zone, comprising: maintaining pressure within the communication zone above a predetermined high pressure during a high pressure production phase, in and during at least a fraction of the high pressure production phase, supplying the first production-initiating fluid to the communication zone such that: mobilization of producible hydrocarbon material within the communication zone is effected, and such that the mobilized hydrocarbon material is conducted to the production well and produced via the production well; and at least a fraction of the supplied non-condensable gaseous material becomes dissolved within hydrocarbon material disposed within the communication zone; effecting a reduction in pressure of the communication zone from above the predetermined high pressure to below a predetermined low pressure such that at least a fraction of the dissolved non-condensable gaseous material becomes liberated from solution within the hydrocarbon material and, upon the liberation, expands and thereby at least contributes to driving the mobilized hydrocarbon material to the production well; after the effected reduction in pressure, maintaining pressure within the communication zone below the predetermined low pressure during a lower pressure production phase; effecting an increase in pressure of the communication zone from below the predetermined low pressure to above the predetermined low pressure; and repeating steps through, at least once.

1 . A process for producing hydrocarbon material from a hydrocarbon reservoir through a production well that is disposed in fluid communication with an iniection well via an interwell region disposed within a communication zone, comprising:
 (a) maintaining pressure within the communication zone above a predetermined high pressure during a high pressure production phase, and during at least a fraction of the high pressure production phase, supplying the first production-initiating fluid to the communication zone such that:
 (i) mobilization of producible hydrocarbon material within the communication zone is effected, and such that the mobilized hydrocarbon material is conducted to the production well and produced via the production well; and 
 (ii) at least a fraction of the supplied non-condensable gaseous material becomes dissolved within hydrocarbon material disposed witbin the communication zone; 
   (b) effecting a reduction in pressure of the communication zone from above the predetermined high pressure to below a predetermined iow pressure such that at least a fraction of the dissolved non-condensable gaseous material becomes liberated from soiution within the hydrocarbon material and, upon the liberation, expands arid thereby at least contributes to driving the mobilized hydrocarbon material to the production well:   (c) affer the effected reduction in pressure, maintaining pressure within the communication zone below the predetermined low pressure during a lower pressure production phase;   (d) effecting an increase in pressure of the communication zone from below the predetermined low pressure to above the predetermined low pressure; and   (e) repeating steps (a) through (d), at least once,   
     
     
         2 . The process as claimed in  claim 1 ;
 wherein the supplying of the first production initiating fluid to the communication zone is effected during the entirety or the substantial entirety, of the high pressure production phase.   
     
     
         3 . The process as claimed in  claim 1 ;
 wherein the concentration of the non-condensable gaseous material within the first production-initiating fluid is greater than 0.1 mol %   
     
     
         4 . The process as claimed in  claim 3 ;
 wherein the concentration of the non-condensable gaseous material within the first production-initiating fluid is between 0.1 mol % and 20 mol %   
     
     
         5 . The process as claimed in  claim 4 ;
 wherein the concentration of the non-condensable gaseous materiai within the first production-initiating fluid is between 1.0 mol % and 2.0 mol %.   
     
     
         6 . The process as claimed in  claim 1 ;
 wherein the duration of the high pressure production phase is greater than 30 days;   and wherein the duration of the low pressure production phase is greater than 30 days.   
     
     
         7 . The process as claimed in  claim 6 ;
 wherein the duration of the high pressure phase is between 30 days and 180 days;   and wherein the duration of the low pressure production phase is between 30 days and 180 days.   
     
     
         8 . The process as claimed in  claim 1 ;
 wherein steps (a) through (d) are repeated at least twice,   
     
     
         9 . The process as claimed in  claim 8 ;
 wherein steps (a) through (d) are repeated at least three times.   
     
     
         10 . The process as claimed in  claim 1 ;
 wherein the concentration of the non-condensable gaseous material within the first productionnitiating fluid during step (a) of a later cycle is greater relative to the concentration of the non-condensable gaseous material within the fia)t production-initiating fluid during step (a) of an earlier cycle   
     
     
         11 . The process as claimed in  claim 1 :
 wherein the difference, between: (a) the maximum pressure differential between the injection and production wells during the higher pressure production phase, and (b)) the maximum pressure differentia between the injection and production wells during the lower pressure production phase, is less than 200 kPA, and includes zero difference or substantialiy no difference.   
     
     
         12 . The process as claimed in  claim 1 ,
 wherein the non-condensable gaseous material of the first production-initiating fluid includes at least 50 volume % of relatively soluble material, based on the total volume of non-condensable gaseous material, wherein the reaitively soluble material is selected from the group consisting of CH 4 , CO 2 , and a composition of CH 4  and CO 2     
     
     
         13 . The process as claimed in  claim 1 ;
 wherein, during at least a fraction of the low pressure production phase, supplying of a second production-initiating fluid is effected to the communication zone,   
     
     
         14 . The process as claimed in  claim 13 :
 wherein the second production-initiating fluid includes steam.   
     
     
         15 . The process as claimed in  claim 13 ,
 wherein the supplying of the second production initiating fluid to the communication zone is effected during the entirety, or the substantial entirety, of the low pressure production phase.   
     
     
         16 . The process es claimed in  claim 13 ;
 wherein the concentration of non-condensable gaseous material of the second production-initiating fluid, if any, is less than the concentration of non-condeneabie gaseous material of the first production-initiating fluid.   
     
     
         17 . The process as claimed in  claim 16   wherein the concentration of non-condensable gaseous material of the second production-initiating fluid is less than 50% of the concentration of non-condensable gaseous material of the first production-intiating fluid, and inciudes zero concentration or substantially zero concentration.   
     
     
         18 . A process for producing hydrocarbon material from a hydrocarbon reservoir through a production well that is disposed in fluid communication with en injection well via an intemell region disposed within a communication zone, comprising:
 (a) supplying a first production-initiating fluid, inciuding steam and no gaseous material, to the communication zone of the oil sands reservoir via the injection well such that:
 (i) mobilization of producible hydrocarbon material within the communication zone is effected, and such that the mobilized hydrocarbon material is conducted to the production well and produced via the production well; and 
 (ii) the communication zone becomes disposed above a predetermined high pressure such that at least a fraction of the supplied non-condensable gaseous material becomes dissolved within hydrocarbon material disposed within the communication zone, 
   (b) effecting a reduction in pressure of the communication zone to below a predetermined low pressure such that at least a traction of the dissolved non-condensable gaseous material becomes liberated from solution within the hydrocarbon material and, upon the liberation, expands and thereby drives mobilized hydrocarbon material to the production well; and   (c) after the effected reduction in pressure, maintaining pressure within the communication zone below the predetermined low pressure during a tower pressure production phase;   wherein the difference, between: (a) the maximum pressure differential between the injection and production wells during the higher pressure production phase, and (b) the maximum pressure differentiai between the injection and production wells during the lower pressure production phase, is less than 200 kPa, and includes zero difference or substantially no difference.   
     
     
         19 . A process for producing hydrocarbon material from a hydrocarbon reservoir through a production well that is disposed in fluid communication with an injection well vie en interwell region disposed within a communication zone, comprising:
 (a) supplying a first production-initiating fluid, including steam and non-condensable gaseous material, to the communication zone of the oil sands reservoir via the injection well such that:
 (i) mobilization of producible hydrocarbon material within the communioation zone is effected, and such that the mobilized hydrocarbon material is conducted to the production well and produced via the production well; and 
 (ii) the communication zone becomes disposed above a predetermined high pressure such that at least a fraction of the supplied non-condensable gaseous material becomes dissolved within hydrocarbon material disposed within the communication zone; 
   (b) effeCting a reduction in pressure of the communication zone to below a predetermined iow pressure such that at least a fraction of the dissolved non-condensable gaseous material becomes liberated from solution within the hydrocarbon material and, upon the liberation, expands and thereby dnves mobilized hydrocarbon material to the production well; and   (c) after the effected reduction in pressure, maintaining pressure within the communication zone below the predetermined low pressure during a lower pressure production phase;   wherein the non-condensabie gaseous material of the first prodUction-initiating fluid includes at least 20 volume % of relatively soluble material, based on the total volume of non-condensable gaseous material, wherein the realtively soiuble material is selected from the group consisting of CH 4 , CO 2 , and a cornposition of CH 4  and CO 2 .   
     
     
         20 . A process for producing hydrocarbon material from a hydrocarbon reservoir through a production well that is disposed in fluid communication with an injection well via an interwell region disposed within a communication zone, comprising:
 (a) supplying a first production-initiating fluid, including steam and non-condensable gaseous material, to the Communication zone of the oil sands reservoir via the injection well that:
 (i) mobilization of producible hydrocarbon material within the communication zone is effected, and such that the mobilized hyijrocarbon material is conducted to the production well and produced via the production well; and 
 (ii) the communication zone becomes disposed above a predetermined high pressure such that at least a fraction of the supplied non- condensable gaseous material becomes dissolved within hydrocarbon material disposed within the communication zone: 
   (b) effecting a reduction in pressure of the communication zone to below a predetermined low pressure such that at least a faction of the dissolved non-condensable gaseous material becomes liberated from solution within the hydrocarbon material and, upon the liberation, expands and thereby drives mobilized hydrocarbon material to the production well; and   (c) after the effected reduction in pressure, maintaining pressure within the communication zone below the predetermined low pressure during a lower pressure production phase;   wherein, during at least a fraction of the low pressure production phase, supplying of a second production-initiating fluid is effected to the communication zone, and wherein the concentration of non-condensable gaseous material of the second production-initiating fluid is less than the concentration of non-condensable gaseous material of the first production-initiating fluid, and includes zero concentration or substantially zero concentration.   
     
     
         21 . The process as claimed in  claim 20 ;
 wherein the second production-initiating includes steam.   
     
     
         22 . The process as claimed in  claim 20 ;
 wherein the supplying of the second production-initiating fluid to the communication zone is effected during the entirety, or the substantial entirety, of the low pressure production phase.   
     
     
         23 . The process as claimed in  claim 20 ;
 wherein the concentration of non-condensable gaseous material of the second production-initiating fluid is ler,:s than 50% of the concentration of non-condensable gaseous material of the first production-initiating fluid, end includes zero concentration or substantially zero concentration.