Thermal pulsing procedure for remediation of cold spots in steam assisted gravity drainage

Abstract

A method for remediation of at least one cold spot in a producer well in a Steam Assisted Gravity Drainage (SAGD) process to increase hydrocarbon recovery from a hydrocarbon reservoir, wherein the SAGD process occurs at a site including an injection well, a production well and a steam chamber. The method includes shutting the production well and maintaining or increasing steam injection through the injection well until pressure in the steam chamber increases. The production well is then resumed while continuing steam injection at rates for normal SAGD or greater until reservoir pressure reaches normal operational pressure. Optionally, the injection/production is adjusted to return to normal SAGD operation.

1 . A method for remediation of at least one cold spot in a producer well in a Steam Assisted Gravity Drainage (SAGD) process, to increase hydrocarbon recovery from a hydrocarbon reservoir, said SAGD process occurring at a site comprising an injection well, a production well, and a steam chamber, wherein said method comprises:
 (a) shutting the production well;   (b) maintaining or increasing steam injection through the injection well until pressure in the steam chamber increases;   (c) resuming the production well while continuing steam injection at rates for normal SAGD or greater, until reservoir pressure reaches normal operational pressure; and optionally   (d) adjusting injection/production to return to normal SAGD operation.   
     
     
         2 . The method of  claim 1  wherein the pressure in the steam chamber increases up to about 0.5 MPa. 
     
     
         3 . The method of  claim 1  wherein the at least one cold spot has a temperature of about 10° C. to 20° C. lower than a SAGD sub cool target temperature. 
     
     
         4 . The method of  claim 1  wherein the at least one cold spot is formed by cold water incursion from a water zone in said reservoir. 
     
     
         5 . The method of  claim 4  wherein the cold water incursion has a water recharge rate from the water zone of less that about 500 m 3 /d. 
     
     
         6 . The method of  claim 1  wherein the reservoir is a heterogeneous Type B reservoir. 
     
     
         7 . The method of  claim 1  wherein the reservoir is a homogeneous Type A reservoir. 
     
     
         8 . The method of  claim 1  wherein the reservoir is a homogeneous Type C reservoir. 
     
     
         9 . The method of  claim 4  wherein the cold water incursion has a water recharge rate from the water zone of less than about 50 m 3 /d. 
     
     
         10 . The method of  claim 1  wherein the pressure in the steam chamber pressure increases up to less than or equal to about 0.3 MPa. 
     
     
         11 . The method of  claim 3  wherein the at least one cold spot is at least about 20° C. lower than SAGD sub cool target temperature. 
     
     
         12 . The method of  claim 2  wherein the at least one cold spot is formed by cold water incursion from a water zone in said reservoir. 
     
     
         13 . The method of  claim 3  wherein the at least one cold spot is formed by cold water incursion from a water zone in said reservoir.