Method for zonal extensional production of hydrocarbons

Abstract

A method for producing hydrocarbons from a subsurface reservoir involves identifying hydraulically isolated target and trigger reservoirs. A fluid is produced from the trigger reservoir to create an extension zone in the target reservoir. A portion of the extension zone is subjected to an action such as zonal dilation, zonal extension, extensional mechanical fracturing, opening of natural fractures, pore volume expansion, and/or microfracturing of mineral grains and grain cements. Production of the trigger reservoir fluid is ceased and then a hydrocarbon is produced from the target reservoir.

What is claimed is: 
     
         1 . A method for production of a hydrocarbon from a subsurface reservoir, comprising the steps of:
 a) identifying a target reservoir, the target reservoir bearing hydrocarbons;   b) locating a trigger reservoir proximate the target reservoir, the trigger reservoir being hydraulically isolated from the target reservoir;   c) producing a fluid from the trigger reservoir, thereby creating an extension zone in the target reservoir, wherein a portion of the target reservoir having the extension zone is subjected to an action selected from the group consisting of zonal dilation, zonal extension, extensional mechanical fracturing, opening of natural fractures, pore volume expansion, microfracturing of mineral grains and grain cements, and combinations thereof;   d) ceasing production of the fluid from the trigger reservoir; and   e) producing a hydrocarbon selected from oil, gas and combinations thereof from the target reservoir.   
     
     
         2 . The method of  claim 1 , wherein step (c) comprises creating at least one of a compression zone and a compaction zone in the trigger reservoir. 
     
     
         3 . The method of  claim 1 , wherein the trigger reservoir is hydraulically isolated from the primary reservoir with a layer of impervious rock. 
     
     
         4 . The method of  claim 1 , wherein the trigger reservoir is comprised of a brine-saturated rock and the fluid is brine. 
     
     
         5 . The method of  claim 1 , wherein the fluid in the trigger reservoir is comprised of brine, water, and/or hydrocarbons. 
     
     
         6 . The method of  claim 1 , wherein step (c) comprises a hard drawdown in the trigger reservoir. 
     
     
         7 . The method of  claim 1 , further comprising the step of hydraulically stimulating the target reservoir after step (d) and/or step (e). 
     
     
         8 . The method of  claim 1 , further comprising the step of hydraulically fracturing the target reservoir before step (a) and/or step (c). 
     
     
         9 . The method of  claim 1 , wherein a well used for producing fluids from the trigger reservoir is vertically disposed. 
     
     
         10 . The method of  claim 1 , wherein a well used for producing hydrocarbons from the target reservoir is vertically disposed. 
     
     
         11 . The method of  claim 1 , wherein a well used for producing fluids from the trigger reservoir is horizontally disposed. 
     
     
         12 . The method of  claim 1 , wherein a well used for producing hydrocarbons from the target reservoir is horizontally disposed. 
     
     
         13 . The method of  claim 1 , wherein the trigger reservoir is located below the target reservoir. 
     
     
         14 . The method of  claim 1 , wherein the trigger reservoir is located above the target reservoir. 
     
     
         15 . The method of  claim 1 , wherein steps (c) are repeated. 
     
     
         16 . The method of  claim 1 , wherein the target reservoir has a relatively low permeability, relatively immobile hydrocarbons, and combinations thereof.