Thermally induced expansion drive in heavy oil reservoirs

Abstract

Aspects of the disclosure involve the production of hydrocarbons from segregated reservoir compartments. Thermal recovery processes within one compartment are used so as to provide thermal energy to a second, adjoining but distinct compartment, increasing fluid pressures within the second compartment to drive hydrocarbons from the second compartment to the first compartment, so that hydrocarbons originating from the second compartment may be produced from the first compartment.

What is claimed is: 
     
         1 . A process for mobilizing fluids in a subterranean formation, the process comprising:
 a) selecting a hydrocarbon reservoir in the formation bearing heavy oil, the reservoir having a primary heavy oil compartment hydraulically separated from a secondary heavy oil compartment by a permeability barrier, wherein under initial reservoir conditions heavy oil does not flow across the permeability barrier, and wherein the secondary heavy oil compartment is hydraulically confined;   b) applying a thermal recovery technique to the primary heavy oil compartment to mobilize heavy oil therein, so that thermal energy applied to the primary heavy oil compartment is communicated across the permeability barrier to the secondary heavy oil compartment to heat heavy oil in the secondary heavy oil compartment so as to increase fluid pressure within the secondary heavy oil compartment;   c) adjusting the production and/or injection of fluids in the primary heavy oil compartment and the delivery of thermal energy to the secondary heavy oil compartment, so that the fluid pressure in the secondary heavy oil compartment rises above the fluid pressure in the primary heavy oil compartment to create a fluid pressure differential between the compartments;   d) providing a fluid flow path across the permeability barrier so that mobilized heavy oil flows from the secondary heavy oil compartment to the primary heavy oil compartment, driven by the fluid pressure differential between the compartments.   
     
     
         2 . The method of  claim 1 , further comprising recovering a produced fluid from the primary heavy oil compartment, wherein the produced fluid comprises heavy oil from the secondary heavy oil compartment. 
     
     
         3 . The method of  claim 2 , wherein the production and injection of fluids in the primary heavy oil compartment and the delivery of thermal energy to the secondary heavy oil compartment is carried out by a steam assisted gravity drainage process in the primary heavy oil compartment, comprising a SAGD injection well and a SAGD production well placed in the primary heavy oil compartment. 
     
     
         4 . The method of  claim 3 , wherein the produced fluid from the primary heavy oil compartment is recovered through the SAGD production well. 
     
     
         5 . The method of  claims 1 , wherein the primary heavy oil compartment is generally below the secondary heavy oil compartment. 
     
     
         6 . The method of  claim 1 , wherein the secondary heavy oil compartment is hydraulically confined by a static seal formed by a geological pattern of surrounding permeability barriers. 
     
     
         7 . The method of  claim 1 , wherein the secondary heavy oil compartment is hydraulically confined at least in part by the imposition of a dynamic fluid flow barrier. 
     
     
         8 . The method of  claim 1 , wherein an additional drive mechanism is applied to the secondary heavy oil compartment to enhance fluid flow from the secondary compartment to the primary compartment. 
     
     
         9 . The method of  claim 8 , wherein the additional drive mechanism is one or more of: cyclic steam stimulation, hot water flood, or steam flood. 
     
     
         10 . The method of  claim 1 , wherein the fluid flow path across the permeability barrier is a well having a horizontal trajectory component and a vertical trajectory component.