Recovery From A Hydrocarbon Reservoir

Abstract

A method and systems for improving recovery from a hydrocarbon reservoir are described. A method includes identifying an interval within the reservoir that comprises a reduced reservoir quality, wherein the interval includes hydrocarbons. A production chamber is formed in a reservoir interval below the interval of reduced reservoir quality, wherein the production chamber is in contact with the interval of reduced reservoir quality. Hydrocarbons are mobilized in the interval of reduced reservoir quality by contact with a mobilizing agent and a pressure is changed within the interval of reduced reservoir quality to allow hydrocarbon flow from the interval of reduced reservoir quality.

What is claimed is: 
     
         1 . A method for improving recovery from a hydrocarbon reservoir, comprising:
 identifying an interval within the reservoir that comprises a reduced reservoir quality, wherein the interval comprises hydrocarbons;   forming a production chamber in a reservoir interval below the interval of reduced reservoir quality, wherein the production chamber is in contact with the interval of reduced reservoir quality;   mobilizing hydrocarbons in the interval of reduced reservoir quality by contact with a mobilizing agent; and   changing a pressure within the interval of reduced reservoir quality to allow hydrocarbon flow from the interval of reduced reservoir quality.   
     
     
         2 . The method of  claim 1 , comprising cycling a steam pressure within the production chamber. 
     
     
         3 . The method of  claim 1 , comprising cycling a solvent pressure within the production chamber. 
     
     
         4 . The method of  claim 1 , comprising cycling the pressure over a period of at least one month. 
     
     
         5 . The method of  claim 1 , comprising cycling different areas of a reservoir using offset pressure phases to keep the total injection rate of the mobilizing fluid substantially constant over time. 
     
     
         6 . The method of  claim 1 , comprising drilling a lateral segment through the interval of reduced reservoir quality, wherein the lateral segment is configured to allow mobilizing agent flow into the interval of reduced reservoir quality. 
     
     
         7 . The method of  claim 6 , comprising drilling the lateral section through the intervals of reduced reservoir quality at an angle to a bed dip. 
     
     
         8 . The method of  claim 6 , comprising drilling the lateral section as a side track drilled from one of the gravity drainage wellbores. 
     
     
         9 . The method of  claim 6 , comprising leaving the lateral section open to the production chamber. 
     
     
         10 . The method of  claim 6 , comprising completing the portion of the lateral segment that is within the interval of reduced reservoir quality with a slotted liner, a wirewrap screen, or a mesh rite screen. 
     
     
         11 . The method of  claim 6 , comprising drilling the lateral segment from the surface. 
     
     
         12 . A system for increasing hydrocarbon production from an interval of low quality reservoir, comprising:
 an injection well configured to inject an injectant into a reservoir;   a production well configured to produce fluids from the reservoir, wherein the fluids comprise a hydrocarbon; and   a pressure system configured to change a pressure within a production chamber to increase a flow of hydrocarbon from an interval of low quality reservoir in contact with the production chamber.   
     
     
         13 . The system of  claim 12 , wherein a maximum operating pressure for the production chamber is less than a reservoir failure pressure. 
     
     
         14 . The system of  claim 12 , wherein a minimum operating pressure for the production chamber is at least 10% lower than a maximum operating pressure. 
     
     
         15 . The system of  claim 12 , wherein the pressure system comprises an injection system configured to lower the pressure by slowing an injection rate. 
     
     
         16 . The system of  claim 12 , wherein the pressure system comprises a production system configured to lower the pressure by increasing fluid withdrawal. 
     
     
         17 . The system of  claim 12 , comprising a plurality of injection and production well pairs, and wherein the pressure of a production chamber associated with a single one of the plurality of injection and production well pairs is cycled. 
     
     
         18 . The system of  claim 17 , wherein two or more production chambers are independently pressure cycled, wherein each production chamber is associated with one of the plurality of injection and production well pairs. 
     
     
         19 . The system of  claim 12 , wherein the injection well and production well are drilled parallel to the direction of a bed dip in the lower quality resource. 
     
     
         20 . A system for harvesting resources in a low quality interval of a reservoir, comprising:
 a gravity drainage system configured to drain a first portion of resources from a high quality interval of a reservoir; and   a pressure control system, wherein the pressure control system is configured to change a pressure on a production chamber to drain a second portion of resources from a low quality interval of a reservoir.